Re: Advocacy URL for publishing data with an explicit license
Talis has written about this issue or encouraged others to write for quite a while. Here are a few links. There are probably others I have forgotten about. http://blogs.talis.com/nodalities/2010/02/sharing-data-on-the-web.php http://blogs.talis.com/nodalities/2009/07/linked-data-public-domain.php http://blogs.talis.com/nodalities/2007/07/open_data_licensing_an_unnatur.php HTH Ian On Monday, October 24, 2011, Richard Cyganiak rich...@cyganiak.de wrote: Dear list, We all know that data publishers *should* publish their data along with an explicit license that explains what kind of re-use is allowed. Can anyone suggest a good reference/link/URL that makes this case? A blog post or advocacy site or similar? Bonus points if it has specific recommendations for RDF. My preferred candidate so far is this – but it's not particularly strong on the “why”: http://www.w3.org/TR/void/#license Thanks, Richard
Re: Linked Data visualisation of Indices of Multiple Deprivation
Very nice! On 8 Sep 2011 17:58, Bill Roberts b...@swirrl.com wrote: The list might be interested in a prototype application built by Steve Peters that visualises and links up data on: - the English Indices of Multiple Deprivation from http://opendatacommunities.org (which I was involved with) - schools (from the data.gov.uk Edubase dataset) - councillors (from OpenlyLocal) - MPs (from theyworkforyou) helped also by other APIs including Mapit, Geonames, Google maps... It's one of the nicest examples I've seen of this kind of mashup and shows off what it means to be truly linked. It uses capital letters Linked Data where appropriate and available, but also pulls in stuff from all kinds of other APIs too. Blog post here: http://openviz.wordpress.com/2011/09/08/indices-of-deprivation-linked-data-prototype/ App itself here: http://dclgexamples.mywebcommunity.org/imd_demo_v7.htm Bill Roberts
Re: Squaring the HTTP-range-14 circle
On Fri, Jun 17, 2011 at 12:35 PM, Dave Reynolds dave.e.reyno...@gmail.com wrote: On Thu, 2011-06-16 at 21:22 -0400, Tim Berners-Lee wrote: On 2011-06 -16, at 16:41, Ian Davis wrote: The problem here is that there are so few things that people want to say about web pages compared with the multitude of things they want to say about every other type of thing in existence. Well, that is a wonderful new thing. For a long while it was difficult to put data on the web, while there is quite a lot of metadata. Wonderful idea that the semantic web may be beating the document web hands down but that's not totally clear that we should trash the use of URIs for use to refer to documents as do in the document web. I'm sure Ian wasn't claiming the data web is beating the document web and equally sure that you don't really think he was :) Yes, absolutely. FWIW my experience is also that most of the data that people want to publish *in RDF* is about things rather than web pages. Clearly there *are* good use cases for capturing web page metadata in RDF but I've not seen that many in-the-wild cases where people wanted to publish data about *both* the web page and the thing. That's why Ian's Back to Basics suggestion works for me [as a fall back from just use #]. My interpretation is that, unlike most of this thread, it wasn't saying use URIs ambiguously but saying the interpretation of the URI is up to the publisher and is discovered from the data not from the protocol response, it is legitimate to use a http-no-# URI to denote a thing if that is what you really want to do. Yes, that's exactly what I am saying. Thus if I want to publish a table of e.g. population statistics at http://foobar.gov.uk/datasets/population then I can do so and use that URI within the RDF data as denoting the data set. As publisher I'm saying this is a qb:DataSet not a web page, anything that looks like a web page when you point a browser at it is just a rendering related to that data and that rendering isn't being given a separate URI so you can talk about it, sorry about that. If you use HTTP 200 for something different, then you break my ability to look at a page, review it, and then express my review in RDF, using the page's URI as the identifier. Not quite. It is saying that you can't give a review for my http://foobar.gov.uk/datasets/population web page because the RDF returned by the URI says it denotes a dataset not the web page. You can still review the dataset itself. You can review other web pages which don't return RDF data saying they are something other than a web page. [As an aside, I would claim that most reviews are in fact about things - restaurants, books, music - not about the web pages.] Quite. When a facebook user clicks the Like button on an IMDB page they are expressing an opinion about the movie, not the page. Ian
Re: Squaring the HTTP-range-14 circle
On Fri, Jun 17, 2011 at 2:04 PM, Tim Berners-Lee ti...@w3.org wrote: On 2011-06 -17, at 08:51, Ian Davis wrote: If you use HTTP 200 for something different, then you break my ability to look at a page, review it, and then express my review in RDF, using the page's URI as the identifier. Not quite. It is saying that you can't give a review for my http://foobar.gov.uk/datasets/population web page because the RDF returned by the URI says it denotes a dataset not the web page. You can still review the dataset itself. You can review other web pages which don't return RDF data saying they are something other than a web page. [As an aside, I would claim that most reviews are in fact about things - restaurants, books, music - not about the web pages.] Quite. When a facebook user clicks the Like button on an IMDB page they are expressing an opinion about the movie, not the page. BUT when the click a Like button on a blog they are expressing they like the blog, not the movie it is about. AND when they click like on a facebook comment they are saying they like the comment not the thing it is commenting on. And on Amazon people say I found this review useful to like the review on the product being reviewed, separately from rating the product. So there is a lot of use out there which involves people expressing stuff in general about the message not its subject. Sure. All these use cases stand and can co-exist. I can look at the data in any of those responses, or data I glean from elsewhere, to figure out if the URI I'm accessing refers to the content I received or the subject of that content. That model works for any protocol BTW. I am really not sure that I want to give up the ability in my browser to bookmark a page about something -- the IMDB page a about a movie, rather than the movie itself. OK, we differ here then. I would prefer to bookmark the movie because that's what I'm interested in. The page will change over the years but the movie will still persist. Today you have no choice because your conceptual model does not give a URI to the movie and doesn't see the need to generate 2 URIs. When the cost os just fixing Microdata syntax to make it easy to say things about the subject of a page. i don't think this has anything to do with microdata. Ian
Re: Squaring the HTTP-range-14 circle
On Fri, Jun 17, 2011 at 2:04 PM, Tim Berners-Lee ti...@w3.org wrote: Not quite. It is saying that you can't give a review for my http://foobar.gov.uk/datasets/population web page because the RDF returned by the URI says it denotes a dataset not the web page. You can still review the dataset itself. You can review other web pages which don't return RDF data saying they are something other than a web page. [As an aside, I would claim that most reviews are in fact about things - restaurants, books, music - not about the web pages.] Quite. When a facebook user clicks the Like button on an IMDB page they are expressing an opinion about the movie, not the page. BUT when the click a Like button on a blog they are expressing they like the blog, not the movie it is about. AND when they click like on a facebook comment they are saying they like the comment not the thing it is commenting on. And on Amazon people say I found this review useful to like the review on the product being reviewed, separately from rating the product. So there is a lot of use out there which involves people expressing stuff in general about the message not its subject. As an additional point, a review _is_ a seperate thing, it's not a web page. It is often contained within a webpage. It seems you are conflating the two here. Reviews and comments can be and often are syndicated across multiple sites so clearly any liking of the review needs to flow with it. Ian
Re: Squaring the HTTP-range-14 circle
Small typo changed the meaning of what I was saying: On Fri, Jun 17, 2011 at 2:18 PM, Ian Davis li...@iandavis.com wrote: OK, we differ here then. I would prefer to bookmark the movie because that's what I'm interested in. The page will change over the years but the movie will still persist. Today you have no choice because your conceptual model does not give a URI to the movie and doesn't see the need to generate 2 URIs. But I meant to write: Today you have no choice because your conceptual model does not give a URI to the movie and [the publisher] doesn't see the need to generate 2 URIs. Of course I recognise your conceptual model sees the need for multiple URIs... :) Ian
Re: Squaring the HTTP-range-14 circle
Tim, On Thu, Jun 16, 2011 at 6:04 PM, Tim Berners-Lee ti...@w3.org wrote: I don't think 303 is a quick and dirty hack. It does mean a large extension of HTTP to be uses with non-documents. It does have efficiency problems. It is an architectural extension to the web architecture. We have had many years for this architectural extension to be adopted and many of us producing linked data have been diligent in supporting, promoting and educating people about it. Even I, with my many many attempts to get this decision reconsidered, have promoted the W3C consensus. Conversely, many more people have studied this extension and rejected it. Companies such as Google, Facebook, Microsoft and Yahoo, who are all W3C members and can influence these decisions through formal channels if they wish, have looked at the httpRange decsion and decided it doesn't work for them. Instead they have chosen different approaches that require more effort to consume but lower the conceptual barrier for publishers. However, they are convinced of the need for URIs to identify things that are not just web pages which is a huge positive. These companies collectively account for a very large proportion of web traffic and activity. I think just saying that they're wrong and should change their approach is simply being dogmatic. They are telling us that we are wrong. We should listen to them. If you want to give yourself the luxury of being able to refer to the subject of a webpage, without having to add anthing to disambiguate it from the web page, then for the sake of your system, so you can use the billion web pages for your purposes, then you now stop other like me from using semantic web systems to refer to those web pages, or in fact to the other hundred million web pages either. The problem here is that there are so few things that people want to say about web pages compared with the multitude of things they want to say about every other type of thing in existence. Yet the httpRange decision makes the web page a privileged component. I understand why that might have seemed a useful decision, after all this is the web we are talking about, but it has turned out not to be. The web page is only the medium for conveying information about the things we are really interested in. The analogy is metadata about a book. Very little of it is about the physical book, i.e. the medium. Perhaps you would want to record its dimensions, mass, colour, binding or construction. There are many many more things you would want to record about the book's content, themes, people and places mentioned, author etc. Maybe you should an efficient way of doing what you want without destroying the system (which you as well have done so much to build) I think this is unreasonably strong. Nothing is being destroyed. Nothing has broken. A few days after I wrote this post (http://blog.iandavis.com/2010/12/06/back-to-basics/) I changed one of the many linked datasets I maintain to stop using 303 redirects over a few million resources. No-one has noticed yet. Nothing has broken. Ian
Re: Quick reality check please
On Fri, Apr 8, 2011 at 1:21 PM, Richard Cyganiak rich...@cyganiak.de wrote: With the second issue it's not so clear what to do about it. It's a question of good practice, and I'm not aware of any document where that recommendation could be easily added. Maybe it could be written up as a pattern for the Linked Data Patterns book? http://patterns.dataincubator.org/ Ian
Re: Exciting changes at Data.Southampton.ac.uk!
Christopher,
I really don't see why I should have to reengineer my entire toolchain
simply to consume your proprietary format. It is well known that the
standard for information interchange is the Microsoft Word 97 document
format which is easily read by every popular computing package. I for one
will not be submitting to the opression of PDF.
Ian
On 1 Apr 2011 08:29, Christopher Gutteridge c...@ecs.soton.ac.uk wrote:
After some heated debate after the backlash against me for my recent
comments about PDF, I've been forced to shift to recommending PDF as the
preferred format for the data.southampton.ac.uk site, both for
publishing and importing data.
There are some issues with this and I know not every one will be happy
with the decision; it wasn't easy to make... but on reflection, however,
it's the right one. It is much easier for non programmers (the majority
of people) to work with PDF documents and they are supported by pretty
much every platform you can think of with a choice of tools and the
benefit of familiarity.
We've provided a wrapper around 4store to make PDF the default output
mode:
http://sparql.data.southampton.ac.uk/?query=PREFIX+soton%3A+%3Chttp%3A%2F%2Fid.southampton.ac.uk%2Fns%2F%3E%0D%0APREFIX+foaf%3A+%3Chttp%3A%2F%2Fxmlns.com%2Ffoaf%2F0.1%2F%3E%0D%0APREFIX+skos%3A+%3Chttp%3A%2F%2Fwww.w3.org%2F2004%2F02%2Fskos%2Fcore%23%3E%0D%0APREFIX+geo%3A+%3Chttp%3A%2F%2Fwww.w3.org%2F2003%2F01%2Fgeo%2Fwgs84_pos%23%3E%0D%0APREFIX+rdfs%3A+%3Chttp%3A%2F%2Fwww.w3.org%2F2000%2F01%2Frdf-schema%23%3E%0D%0APREFIX+org%3A+%3Chttp%3A%2F%2Fwww.w3.org%2Fns%2Forg%23%3E%0D%0APREFIX+spacerel%3A+%3Chttp%3A%2F%2Fdata.ordnancesurvey.co.uk%2Fontology%2Fspatialrelations%2F%3E%0D%0APREFIX+ep%3A+%3Chttp%3A%2F%2Feprints.org%2Fontology%2F%3E%0D%0APREFIX+dct%3A+%3Chttp%3A%2F%2Fpurl.org%2Fdc%2Fterms%2F%3E%0D%0APREFIX+bibo%3A+%3Chttp%3A%2F%2Fpurl.org%2Fontology%2Fbibo%2F%3E%0D%0APREFIX+owl%3A+%3Chttp%3A%2F%2Fwww.w3.org%2F2002%2F07%2Fowl%23%3E%0D%0A%0D%0ASELECT+%3Fs+WHERE+{%0D%0A%3Fs+%3Fp+%3Fo+.%0D%0A}+LIMIT+10output=pdfjsonp=#results_table
And most information URIs can now be resolved to PDF, but we are
sticking to HTML as the default (for now)
http://data.southampton.ac.uk/products-and-services/FreshFruit.pdf
The full details and rationale are on our data blog
http://blogs.ecs.soton.ac.uk/data/2011/04/01/pdf-selected-as-interchange-format/E
--
Christopher Gutteridge -- http://id.ecs.soton.ac.uk/person/1248
You should read the ECS Web Team blog:
http://blogs.ecs.soton.ac.uk/webteam/
Re: Exciting changes at Data.Southampton.ac.uk!
On Fri, Apr 1, 2011 at 10:14 AM, Richard Cyganiak rich...@cyganiak.de wrote: Taking advantage of one of PDF's many advantages, we plan to present the first printed and bound version of the complete Linked PDF Data at next years' LDOW workshop. Order your copy now! Shipping fees not included. See, this is where we differ. Your radical ideas about enabling print in the PDFs just won't get traction in real businesses. Ian
Re: data schema / vocabulary / ontology / repositories
Please try http://schemapedia.com/ and see if it meets your needs. On 13 Mar 2011 16:23, Dieter Fensel dieter.fen...@sti2.at wrote: Dear all, for a number of projects I was searching for vocabularies/Ontologies to describe linked data. Could you please recommend me places where to look for them? I failed to find a convenient entrance point for such kind of information. I only found some scattered information here and there? Thanks, Dieter -- Dieter Fensel Director STI Innsbruck, University of Innsbruck, Austria http://www.sti-innsbruck.at/ phone: +43-512-507-6488/5, fax: +43-512-507-9872
Re: The truth about SPARQL Endpoint availability
Is the number of triples that important? With all respect to the
people on this list, I think there's a tendency to obsess over triple
counts. Aren't we past that bootstrap phase of being awed when we see
millions of triples being produced? I thought we'd moved towards
being more focussed on quality and utility of data than sheer numbers?
Besides, for me the most interesting datasets are those that are
continually changing as they reflect the real world and I'd like to
see us work towards metrics for freshness and coverage.
On Sun, Mar 6, 2011 at 11:20 AM, Tim Berners-Lee ti...@w3.org wrote:
Maybe the count of triples should be special-cased in the sparql server code,
spotted on input and the store size returned.
if it is reasonable for the endpoint to keep track of the size of its store.
(Do they anyway?)
Tim
On 2011-03 -05, at 11:58, Bill Roberts wrote:
Thanks Hugh - as someone running a couple of SPARQL endpoints, I'd certainly
prefer if people don't run a global count too often (or at all). It is
indeed something that makes typical SPARQL implementations work very hard.
But it's a good reminder we should provide an alternative and i'll look into
providing triple counts in voiD.
Bill
On 5 Mar 2011, at 15:14, Hugh Glaser wrote:
Hi,
On 5 Mar 2011, at 14:22, Andrea Splendiani wrote:
Hi,
I think it depends on the store, I've tried some (from the endpoint list)
and some returns a answer pretty quickly. Some doesn't and some doesn't
support count.
However, one could have this information only for the stores that answers
the count query, no need to try all time.
I am happy for a store implementor or owner to disagree, but I find it very
unlikely that the owner of a store with a decent chunk of data ( 1M
triples, say) would be happy for someone to keep issuing such a query, even
if they did decide to give enough resources to execute it.
I would quickly blacklist such a site.
VoID:
is this a good query:
select * where {?s http://rdfs.org/ns/void#numberOfTriples ?o }
I'm no SPARQL or voiD guru, but I think you need a bit more wrapping in the
scovo stuff, so more like:
SELECT DISTINCT ?endpoint ?uri ?triples ?uris WHERE
{ ?ds a void:Dataset .
?ds void:sparqlEndpoint ?uri .
?ds rdfs:label ?endpoint .
?ds void:statItem [ scovo:dimension void:numberOfTriples ;
rdf:value ?triples ] .
}
Try it at
http://kwijibo.talis.com/voiD/
or
http://void.rkbexplorer.com/
I guess Pierre-Yves might like to enhance his page by querying a voiD store
to also give basic stats.
Or someone might like to do a store reporter that uses (a) voiD endpoint(s)
plus Pierre-Yves's data (he has a SPARQL endpoint), to do so.
And maybe the CKAN endpoint would have extra useful data as well.
A real Semantic Web application that queried more than one SPARQL endpoint
- now that would be a novelty!
Fancy the challenge, it is the weekend?! :-)
ciao
Hugh
it doesn't seem viable if so.
ciao,
Andrea
Il giorno 05/mar/2011, alle ore 13.49, Hugh Glaser ha scritto:
NIce idea, but,... :-)
SELECT (count(*) as ?c) WHERE {?s ?p ?o}
is a pretty anti-social thing to do to a store.
At best, a store of any size will spend a while thinking, and then quite
rightly decide they have burnt enough resources, and return some sort of
error.
For a properly maintained site, of course, the VoiD description will give
lots of similar information.
Best
Hugh
On 5 Mar 2011, at 13:06, Andrea Splendiani wrote:
Hi, very nice!
I have a small suggestion:
why don't you ask count(*) where {?s ?p ?o} to the endpoint ?
Or ask for the number of graphs ?
Both information, number of triples and number of graphs, if logged and
compared over time, can give a practical view of the liveliness of the
content of the endpoint.
best,
Andrea Splendiani
Il giorno 28/feb/2011, alle ore 18.55, Pierre-Yves Vandenbussche ha
scritto:
Hello all,
you have already encountered problems of SPARQL endpoint accessibility ?
you feel frustrated they are never available when you need them?
you develop an application using these services but wonder if it is
reliable?
Here is a tool [1] that allows you to know public SPARQL endpoints
availability and monitor them in the last hours/days.
Stay informed of a particular (or all) endpoint status changes through
RSS feeds.
All availability information generated by this tool is accessible
through a SPARQL endpoint.
This tool fetches public SPARQL endpoints from CKAN open data. From
this list, it runs tests every hour for availability.
[1] http://labs.mondeca.com/sparqlEndpointsStatus/index.html
[2] http://ckan.net/
Pierre-Yves Vandenbussche.
Andrea Splendiani
Senior Bioinformatics Scientist
Centre for Mathematical and Computational Biology
+44(0)1582 763133 ext 2004
andrea.splendi...@bbsrc.ac.uk
--
Hugh Glaser,
Intelligence, Agents, Multimedia
Re: Google's structured seach talk / Google squared UI
Hi, I did something very similar to Google Squared in small php script a couple of years ago: http://iandavis.com/2009/lodgrid/?store=spacequery=jupitercolumns=6 It uses linked data held in the Talis Platform and the platform's full text search service. More examples linked from the main page: http://iandavis.com/2009/lodgrid/ Ian On Fri, Feb 11, 2011 at 10:23 AM, Daniel O'Connor daniel.ocon...@gmail.com wrote: Hi all, This talk might have been seen by some of you; but was certainly new to me: http://www.youtube.com/watch?v=5lCSDOuqv1Afeature=autoshare Much of this is an exploration of how google is making use of freebase's underlying linked data to better understand what they are crawling - deriving what something is by examining its attributes; and automatically creating something like linked data from it. Additionally; it talks about Google squared - this tool appears to be heavily powered by freebase data; as well as derived data from the web. I was fairly impressed by the mix of understanding a user query and rendering results as actual entities (one of the few non-facet based UIs I have seen). For instance: territorial authorities in new zealand http://www.google.com/squared/search?q=territorial+authorities+in+new+zealand Whilst this is not using the typical linked data technology stack of RDF, SPARQL, open licenced data, etc; it certainly shows you what can be done with data in a graph structure; plus a UI which is a cross between a spreadsheet and a search result.
Re: Google's structured seach talk / Google squared UI
Give me a break, it was only an hour or so's work! :) Seriously, what you suggest is possible with a bit more effort. On Friday, February 11, 2011, Juan Sequeda juanfeder...@gmail.com wrote: Nice! But unfortunately I have to choose a platform store. Shouldn't I be able to search for jupiter and return results from nasa and dbpedia?Juan Sequeda +1-575-SEQ-UEDA www.juansequeda.com On Fri, Feb 11, 2011 at 5:03 AM, Ian Davis li...@iandavis.com wrote: Hi, I did something very similar to Google Squared in small php script a couple of years ago: http://iandavis.com/2009/lodgrid/?store=spacequery=jupitercolumns=6 It uses linked data held in the Talis Platform and the platform's full text search service. More examples linked from the main page: http://iandavis.com/2009/lodgrid/ Ian On Fri, Feb 11, 2011 at 10:23 AM, Daniel O'Connor daniel.ocon...@gmail.com wrote: Hi all, This talk might have been seen by some of you; but was certainly new to me: The Structured Search Engine http://www.youtube.com/watch?v=5lCSDOuqv1Afeature=autoshare Much of this is an exploration of how google is making use of freebase's underlying linked data to better understand what they are crawling - deriving what something is by examining its attributes; and automatically creating something like linked data from it. Additionally; it talks about Google squared - this tool appears to be heavily powered by freebase data; as well as derived data from the web. I was fairly impressed by the mix of understanding a user query and rendering results as actual entities (one of the few non-facet based UIs I have seen). For instance: territorial authorities in new zealand http://www.google.com/squared/search?q=territorial+authorities+in+new+zealand Whilst this is not using the typical linked data technology stack of RDF, SPARQL, open licenced data, etc; it certainly shows you what can be done with data in a graph structure; plus a UI which is a cross between a spreadsheet and a search result.
Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)
On Tue, Nov 9, 2010 at 11:23 AM, Nathan nat...@webr3.org wrote: Pete Johnston wrote: This document mentions the following class It's all very simple really, when you remove all the conflated terms. I am not conflating terms and nor is my example, but I think you are (see below) What is this: ?xml version=1.0? rdf:RDF xmlns:rdf=http://www.w3.org/1999/02/22-rdf-syntax-ns#; xmlns:foaf=http://xmlns.com/foaf/0.1/; xmlns:rdfs=http://www.w3.org/2000/01/rdf-schema#; xmlns:wdrs=http://www.w3.org/2007/05/powder-s#; xmlns:dbp=http://dbpedia.org/resource/; dbp:Toucan rdf:about=http://iandavis.com/2010/303/toucan; rdfs:labelA Toucan/rdfs:label foaf:depiction rdf:resource=http://upload.wikimedia.org/wikipedia/commons/thumb/6/6d/Pteroglossus-torquatus-001.jpg/250px-Pteroglossus-torquatus-001.jpg; / rdfs:commentThis resource is an individual toucan that happens to live in southern mexico./rdfs:comment wdrs:describedby rdf:resource=http://iandavis.com/2010/303/toucan.rdf/ /dbp:Toucan foaf:Document rdf:about=http://iandavis.com/2010/303/toucan.rdf; rdfs:labelA Description of a Toucan/rdfs:label rdfs:commentThis document is a description of the toucan resource./rdfs:comment /foaf:Document /rdf:RDF http://iandavis.com/2010/303/toucan is simply another name for whatever the above is. Nope. It's not at all. That text you include is the entity sent when you issue a GET to the URI. Entity bodies aren't usually named on the web. It's also a representation of http://iandavis.com/2010/303/toucan.rdf You are conflating the resource with the content of an HTTP message sent to your computer. You could interpret the tabulator property as meaning the entity returned when you perform a GET on the URI contains the following class Hints: - it's not a resource It has a URI http://iandavis.com/2010/303/toucan.rdf, anything identified by a URI is a resource. - it's not a document I think it is - it's not an rdf document I think it is - it's not a toucan Agree. That text is not a toucan. Best, Nathan Ian
Publishing Linked Data without Redirects
I wrote up a summary of the current thinking on using 200 instead of 303 to serve up Linked Data: http://iand.posterous.com/a-guide-to-publishing-linked-data-without-red The key part is: When your webserver receives a GET request to your thing’s URI you may respond with a 200 response code and include the content of the description document in the response provided that you: 1. include the URI of the description document in a content-location header, and 2. ensure the body of the response is the same as the body obtained by performing a GET on the description document’s URI, and 3. include a triple in the body of the response whose subject is the URI of your thing, predicate is http://www.w3.org/2007/05/powder-s#describedby and object is the URI of your description document But read the whole post for an example, some theory background and some FAQ. Cheers, Ian
Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)
On Fri, Nov 5, 2010 at 9:53 AM, Leigh Dodds leigh.do...@talis.com wrote: So here's a couple of questions for those of you on the list who have implemented Linked Data tools, applications, services, etc: * Do you rely on or require HTTP 303 redirects in your application? Or does your app just follow the redirect? * Would your application tool/service/etc break or generic inaccurate data if Ian's pattern was used to publish Linked Data. I used Denny Vrandečić's browser tool to test several Linked Data browsers including Tabulator. http://browse.semanticweb.org/?uri=http%3A%2F%2Fiandavis.com%2F2010%2F303%2Ftoucandays=7 Non of these showed any confusion between the toucan and its description, nor did that throw warnings or errors about the lack of 303 or in fact make any reference to it (tabulator includes the response as RDF but does not infer that the 200 response implies a type of information resource, which I had assumed it would) Cheers, Ian
Re: Hash vs Slash in relation to the 303 vs 200 debate (was: Is 303 really necessary - demo)
On Sat, Nov 6, 2010 at 11:31 PM, Toby Inkster t...@g5n.co.uk wrote:
Not necessarily. If you take your ex:isDescribedBy predicate and add
that to a triple store where the non-Information-Resource resources are
identified using hash URIs, then the SPARQL query is just:
DESCRIBE uri ?res
WHERE { ?res ex:isDescribedBy uri . }
which needn't be very slow.
I've done this myself but using foaf:primaryTopic and foaf:topic to
link a document URI to all the resources that are needed to render it.
The other downside of fragments is you can't say it exists but I have
no description of it.
#foo a rdfs:Resource .
In which case you do have a description of it :) But point taken, this
tautology would be enough.
Cheers,
Ian
Re: 200 OK with Content-Location might work
On Sun, Nov 7, 2010 at 7:35 PM, Phil Archer ph...@w3.org wrote: I share John's unease here. And I remain uneasy about the 200 C-L solution. I know I sound like a fundamentalist in a discussion where we're trying to find a practical, workable solution, but is a description of a toucan a representation of a toucan? IMO, it's not. Sure, one can imagine an HTTP response returning a very rich data stream that conveys the entire experience of having a toucan on your desk - but the toucan ain't actually there. The content-location header says that the entity being sent in the response is not a representation of the resource. I don't want to get into a heavy what is a representation really debate because those have been done to minute detail over on the TAG list for many years. Suffice to say that http://www.google.com/ has a representation that is not the entire experience of the google website get that URI denotes the google website for the majoriity of people. I've been toying with the idea of including a substitution rule in a 200 header. I'd prefer not to invent anything new, e.g. new headers or status codes. I'm just looking to simplify an existing set of patterns. My worry is that any 200-based solution is going to be poorly implemented in the real world by both browsers and LOD publishers (Talis excepted of course!) so that IRs and NIRs will be indistinguishable 'in the wild'. My proposal keeps the two separate with distinct URIs. With clear guides, education and testing tools we can encourage people to do the right thing, just like we currently do with any standard. However, philosophically I wonder whether there are any practical consequences of them being indistinguishable. When i read my email in gmail it is hard to separate the email from the webpage allowing me to read the email yet it still works. 303 works already, and that is still the one that feels right to me. I'm happy that the discussion here is centred on adding a new method cf. replacing 303, especially as the HTTP-Bis group seems to have made its use for LOD and explicit part of the definition. It would still be available. My proposal is to provide a streamlined alternative, one that is more in line with what millions of webmasters are doing already. Ian
Re: 200 OK with Content-Location might work
On Fri, Nov 5, 2010 at 4:55 PM, Nathan nat...@webr3.org wrote: Mike Kelly wrote: http://tools.ietf.org/html/draft-ietf-httpbis-p2-semantics-12#page-14 snipped and fuller version inserted: 4. If the response has a Content-Location header field, and that URI is not the same as the effective request URI, then the response asserts that its payload is a representation of the resource identified by the Content-Location URI. However, such an assertion cannot be trusted unless it can be verified by other means (not defined by HTTP). If a client wants to make a statement about the specific document then a response that includes a content-location is giving you the information necessary to do that correctly. It's complemented and further clarified in the entity body itself through something like isDescribedBy. I stand corrected, think there's something in this, and it could maybe possibly provide the semantic indirection needed when Content-Location is there, and different to the effective request uri, and complimented by some statements (perhaps RDF in the body, or Link header, or html link element) to assert the same. Covers a few use-cases, might have legs (once HTTP-bis is a standard?). Nicely caught Mike! +1 This is precisely what we need. Ian
Hash vs Slash in relation to the 303 vs 200 debate (was: Is 303 really necessary - demo)
On Fri, Nov 5, 2010 at 5:28 PM, Nathan nat...@webr3.org wrote: URI resolution is essentially: dereference( uri.toAbsolute() ); Which gives us the simplicity and semantic indirection which we need. Use frags, forget HTTP, know that uri#frag is never going to be a document (unless you explicitly say it is). On a practical level using frags can be inefficient when your linked data output is backed by a triple store. If you use a slash URI then generating the data for html/xml/turtle output is just a simple describe uri. For hash URIs you need to describe all the resources with a common prefix because the fragment is not sent by the browser with the request. That might mean a filter with a regex or string functions which will be more inefficient. If you pick a standard fragment such as #this, #it etc then you can revert to the simple describe so the inefficiency only arises when there are multiple arbitrary fragments per document URI. The other downside of fragments is you can't say it exists but I have no description of it. With standard slash URIs you can 303 to a 404 to say that. You can 404 on the slash itself to say the resource does not exist. With my proposal to use 2xx responses you can return 204 No Content to indicate the resource exists but no description is available. With slashes you can use 410 on an individual resource to indicate that it has gone forever. You can also do this with the one frag per doc approach although you are really saying the description document has gone and the user is left to imply the secondary resource has also gone. With multiple frags per doc (i.e. a lot of schemas) you can't say just one of those resources has gone forever. In summary: Slash with 303: hard static publishing, efficient dynamic, can ack existence without description Hash, one resource per doc: easy static publishing, efficient dynamic, can't ack existence without description Hash, many resources per doc (the typical schema case): easy static publishing, less efficient dynamic, can't ack existence without description Slash with 2xx: easy static publishing, efficient dynamic, can ack existence without description Ian
Is 303 really necessary - demo
Hi all, To aid discussion I create a small demo of the idea put forth in my blog post http://iand.posterous.com/is-303-really-necessary Here is the URI of a toucan: http://iandavis.com/2010/303/toucan Here is the URI of a description of that toucan: http://iandavis.com/2010/303/toucan.rdf As you can see both these resources have distinct URIs. I created a new property http://vocab.org/desc/schema/description to link the toucan to its description. The schema for that property is here: http://vocab.org/desc/schema (BTW I looked at the powder describedBy property and it's clearly designed to point to one particular type of description, not a general RDF one. I also looked at http://ontologydesignpatterns.org/ont/web/irw.owl and didn't see anything suitable) Here is the URI Burner view of the toucan resource and of its description document: http://linkeddata.uriburner.com/about/html/http://iandavis.com/2010/303/toucan http://linkeddata.uriburner.com/about/html/http/iandavis.com/2010/303/toucan.rdf I'd like to use this demo to focus on the main thrust of my question: does this break the web and if so, how? Cheers, Ian P.S. I am not fully caught up on the other thread, so maybe someone has already produced this demo
Re: Is 303 really necessary?
On Fri, Nov 5, 2010 at 9:54 AM, William Waites w...@styx.org wrote: Provenance and debugging. It would be quite possible to record the fact that this set of triples, G, were obtained by dereferencing this uri N, at a certain time, from a certain place, with a request that looked like this and a response that had these headers and response code. The class of information that is kept for [0]. If N appeared in G, that could lead directly to inferences involving the provenance information. If later reasoning is concerned at all with the trustworthiness or up-to-dateness of the data it could look at this as well. Keeping this quantity of information around might quickly turn out to be too data-intensive to be practical, but that's more of an engineering question. I think it does make some sense to do this in principle at least. All the above would remain in my proposal. If you were in fact inferring triples from the 303 then those would already be in the data you are dereferencing. Ian
Re: Is 303 really necessary?
On Fri, Nov 5, 2010 at 10:12 AM, Nathan nat...@webr3.org wrote: What's the point in you saying: /toucan a :Toucan; :describedBy /doc . If the rest of the world is saying: /toucan a :Document; :primaryTopic ex:Toucan . Follow? Because the data obtained by dereferencing /toucan is authoratative? Ian
Re: Is 303 really necessary?
On Fri, Nov 5, 2010 at 10:05 AM, Nathan nat...@webr3.org wrote: Not at all, I'm saying that if big-corp makes a /web crawler/ that describes what documents are about and publishes RDF triples, then if you use 200 OK, throughout the web you'll get (statements similar to) the following asserted: /toucan :primaryTopic dbpedia:Toucan ; a :Document . i don't think so. If the bigcorp is producing triples from their crawl then why wouldn't they use the triples they are sent (and/or content-location, link headers etc). The above looks like what you'd get from a third party translation of the crawl results without the context of actually having fetched the data from the URI. If the bigcorp is not linked data aware then today they will follow the 303 redirect as a standard HTTP redirect. rfc2616 says that the target URI is not a substitute for the original URI but just an alternate location to get a response from. The bigcorp will simply infer the statements you list above **even though there is a 303 redirect**. As rfc2616 itself points out, many user agents treat 302 and 303 interchangeably. Only linked data aware agents will ascribe special meaning to 303 and they're the ones that are more likely to use the data they are sent. Ian
Re: Is 303 really necessary?
On Fri, Nov 5, 2010 at 10:34 AM, Nathan nat...@webr3.org wrote: and if I publish: http://webr3.org/nathan#me :isKingOf :TheWorld . it's authorative and considered true? great news all round :) No :) I mean't that when you dereference http://iandavis.com/2010/303/toucan, the triples you get about http://iandavis.com/2010/303/toucan can be considered authoritative. For me, that's one of the principle advantages of linked data over other data formats - built in provenance if you will. Also authoritative does not mean true. I means it asserts authority over the data. That could very well be wrong, but it's the consumer's choice whether they trust that authority or not (or can prove it perhaps). Ian
Re: Is 303 really necessary?
Hi David, Rather than respond to each of your points let me say that I agree with most of them :) I have snipped away the things I agree with in principle, and left the things I want to discuss further. I have a question about http://thing-described-by.org/ - how does it work when my description document describes multiple things? Really, any RDF document that references more than one resource as a subject or object can be considered to be providing a description of all those resources. On Thu, Nov 4, 2010 at 10:10 PM, David Booth da...@dbooth.org wrote: 2. only one description can be linked from the toucan's URI True, but that's far better than zero, if you only have the toucan URI and it returns 404! It could return 204. 3. the user enters one URI into their browser and ends up at a different one, causing confusion when they want to reuse the URI of the toucan. Often they use the document URI by mistake. Yes, that's a problem. The trade-off is ambiguity. I don't think so. The ambiguity is not present because the data explicitly distinguishes the two URIs (and content-location header does too). 7. it mixes layers of responsibility - there is information a user cannot know without making a network request and inspecting the metadata about the response to that request. When the web server ceases to exist then that information is lost. I don't buy this argument. While I agree that explicit statements such as Utoucan :isDescribedBy Upage . is helpful and should be provided, that does *not* mean that links are not *also* useful. Just because links do not *always* work does not mean that they are useless. But you agree that under the current scheme, some things are knowable only by making a network request. It's not enough to have just the RDF description document? Cheers, Ian
Re: Is 303 really necessary?
On Fri, Nov 5, 2010 at 10:57 AM, Nathan nat...@webr3.org wrote: I'll roll with the who cares line of thinking, I certainly don't care how you or dbpedia or foaf or dc publish your data, so long as I can deref it, but for god sake don't go telling everybody using slash URIs and 200 is The Right Thing TM Sure. We don't want to restrict choice or options. I am focussed here only on simplifying a common pattern. Ian
Re: Is 303 really necessary - demo
On Fri, Nov 5, 2010 at 1:53 PM, Jörn Hees j_h...@cs.uni-kl.de wrote: If I GET http://iandavis.com/2010/303/toucan i retrieve a document (I'll call this A) with rdf statements. This is not correct. You receive a response with an entity: the representation. (Here entity is used in the rfc2616 sense) If I GET http://iandavis.com/2010/303/toucan.rdf i retrieve another document (I'll call this B), which in this case happens to have the same content as A, but could be different, can't it? I could return a different entity, but I wouldn't recommend it. You might want to if you link to multiple descriptions of the resource. Now: how can I say that I don't like A without saying that I don't like http://iandavis.com/2010/303/toucan ? If your answer is going to be say you don't like B again, please explain what happens if A and B don't have the same content. How do you currently refer to the entity transmitted in a HTTP response? You don't - they have no names. How do you say you are offended by something written on twitter's home page when the entity it sends changes every second. Is there some magic involved saying that any ?s with a ?s http://vocab.org/desc/schema/description ?d . is not a document but a real-world object? No. But the description document and the entity returned from the request to /toucan says it's a dbp:Toucan. I would put more credence in explicit statements than implicit ones. Or is there some magic involved that if toucan and toucan.rdf give you the same content that one of them is a real-world object then? No. If not, how can I find out that http://iandavis.com/2010/303/toucan is one and A is only one of its descriptions? Look at the data - it states it clearly. Jörn PS: is there a summary of this discussion somewhere? I'm afraid not, it's only been going a few hours. I haven't seen anything that fundamentally challenges the idea yet, i.e. something that would make me rewrite it. I am seeing several responses arguing that it confuses the thing with the document but I explicitly show how it doesn't in the blog post so I think that comes from people's default assumptions. There are some responses saying don't do that - use fragments instead, but that's no help for the millions of resources already deployed with slash uris and the many people who prefer that style. Other responses have been like yours, seeking more clarity on the ideas. Ian
Re: What would break, a question for implementors? (was Re: Is 303 really necessary?)
On Fri, Nov 5, 2010 at 12:12 PM, Nathan nat...@webr3.org wrote: However, if you use 303's the then first GET redirects there, then you store the ontology against the redirected-to URI, you still have to do 40+ GETs but each one is fast with no response-body (ontology sent down the wire) then the next request for the 303'd to URI comes right out of the cache. It's still 40+ requests unless you code around it in some way, but it's better than 40+ requests and 40+ copies of the single ontology. But in practice, don't you look in your cache first? If you already have a label for foaf:knows because you looked up foaf:mbox a few seconds ago why would you issue another request? Ian
Re: Is 303 really necessary?
On Fri, Nov 5, 2010 at 12:11 PM, Norman Gray nor...@astro.gla.ac.uk wrote: httpRange-14 requires that a URI with a 200 response MUST be an IR; a URI with a 303 MAY be a NIR. Ian is (effectively) suggesting that a URI with a 200 response MAY be an IR, in the sense that it is defeasibly taken to be an IR, unless this is contradicted by a self-referring statement within the RDF obtained from the URI. Thank you for writing this - it's exactly what I mean. Ian
Re: isDefinedBy and isDescribedBy, Tale of two missing predicates
Kingsley, My only gripe is with mutual exclusion. ..dropping 303... didn't come across as adding an option to the mix. Ditto positioning 303 as a mandate, which it's never really been. I think you read too much conspiracy into 140 characters. Ian
Re: isDefinedBy and isDescribedBy, Tale of two missing predicates
On Fri, Nov 5, 2010 at 3:29 PM, Nathan nat...@webr3.org wrote:
Better clear that up, noticed that it's an age old XHTML-RDFa potential
issue, so I'll see if we can get it covered in the WG and relay back to the
TAG to hopefully clear the issue.
Suppose I assign the ID 'mars' to represent the planet mars in my RDFa
document. I can then refer to it using http://example.com/foo#mars.
What does it mean when my javascript calls
document.getElementById('mars')? Should I expect now to manipulate the
planet mars?
This is an analagous dilemma as for slash URIs except the domain is
html + javascript rather than http.
Just like your claimed slash URI problems, in practice it is a
non-issue because people don't really expect to manipulate planets
with javascript. Some dumb machine might assume that in the future but
they are going to make a lot of similar mistakes that will cause a
lot more problems.
Ian
Re: Is 303 really necessary - demo
On Fri, Nov 5, 2010 at 4:42 PM, Robert Fuller robert.ful...@deri.org wrote: I submitted both urls to sindice earlier. Both were indexed and have the same content. In the search results[1] one displays with title A Toucan, the other with title, A Description of a Toucan. http://sindice.com/search?q=toucan+domain%3Aiandavis.comqt=term So SIndice see them as distinct resources and doesn't concern itself with the lack of a 303 redirect? Ian
Is 303 really necessary?
Hi all, The subject of this email is the title of a blog post I wrote last night questioning whether we actually need to continue with the 303 redirect approach for Linked Data. My suggestion is that replacing it with a 200 is in practice harmless and that nothing actually breaks on the web. Please take a moment to read it if you are interested. http://iand.posterous.com/is-303-really-necessary Cheers, Ian
Re: Is 303 really necessary?
On Thu, Nov 4, 2010 at 2:13 PM, Kingsley Idehen kide...@openlinksw.com wrote: Ian, Q: Is 303 really necessary? A: Yes, it is. Why? Read on... I don't think you explain this in your email. What's the problem with having many options re. mechanics for associating an HTTP based Entity Name with a Descriptor Resource Address? Do you mean associate a resource with a description? Or do you mean something else? Can you rephrase using the terminology that everyone else uses please. We shouldn't be narrowing options for implementing the fundamental essence of Linked Data -- hypermedia based data representation. Of course, we can discuss and debate individual, product, or organization preferences etc.. But please lets not push these as mandates. We should never mandate that 303's are bad, never. Its an implementation detail, no more no less. I'm suggesting that we relax a mandate to always use 303 and since you're saying we must not narrow options then you seem to be supporting my suggestion, The only thing that should be mandatory re. Linked Data is this: HTTP based Entity Names should Resolve to structured Descriptors that are Human and/or Machine decipherable. Are you saying that requesting a URI should return a description document? Ironically, bearing in mind my comments, we do arrive at the same conclusion, but in different ways. I phrase my conclusion as: heuristics for implementing HTTP based Entity Names that Resolve to structured Descriptor Resources shouldn't dominate the Linked Data narrative, especially as comprehension of the fundamental concept remains mercurial. So are you contradicting your answer at the start of the post? -- Regards, Kingsley Idehen Ian
Re: Is 303 really necessary?
On Thu, Nov 4, 2010 at 3:00 PM, Kingsley Idehen kide...@openlinksw.com wrote: On 11/4/10 10:22 AM, Ian Davis wrote: On Thu, Nov 4, 2010 at 2:13 PM, Kingsley Idehenkide...@openlinksw.com wrote: Ian, Q: Is 303 really necessary? A: Yes, it is. Why? Read on... I don't think you explain this in your email. What's the problem with having many options re. mechanics for associating an HTTP based Entity Name with a Descriptor Resource Address? Do you mean associate a resource with a description? Or do you mean something else? Can you rephrase using the terminology that everyone else uses please. Who is everyone else? How about the fact that terminology that you presume to be common is actually uncommon across broader spectrum computing. I don't presume. I prefer to use terms that are familiar with the people on this list who might be reading the message. Introducing unnecessary capitalised phrases distracts from the message. Anyway, translation: What's the problem with having a variety of methods for using LINKs to associate a Non Information Resource with an Information Resource that describes it (i.e., carries its structured representation)? Why place an implementation detail at the front of the Linked Data narrative? It's already at the front, and as I say in my post it's an impediment to using Linked Data by mainstream developers. This is an implementation detail that I think could do with improving, making it simpler and in fact removing it from the front of the narrative. It just becomes like commonplace web publishing. Do you agree that's a good goal to strive for? We shouldn't be narrowing options for implementing the fundamental essence of Linked Data -- hypermedia based data representation. Of course, we can discuss and debate individual, product, or organization preferences etc.. But please lets not push these as mandates. We should never mandate that 303's are bad, never. Its an implementation detail, no more no less. I'm suggesting that we relax a mandate to always use 303 and since you're saying we must not narrow options then you seem to be supporting my suggestion, I didn't know there was a mandate to always use 303. Hence my comments. There is. I find it surprising that you're unaware of it because it's in all the primary documents about publishing Linked Data. The only thing that should be mandatory re. Linked Data is this: HTTP based Entity Names should Resolve to structured Descriptors that are Human and/or Machine decipherable. Are you saying that requesting a URI should return a description document? Resolve to a Descriptor Document which may exist in a variety of formats. Likewise, Descriptor documents (RDF docs, for instance) should clearly identify their Subject(s) via HTTP URI based Names. Example (in this example we have 1:1 re. Entity Name and Descriptor for sake of simplicity): http://dbpedia.org/resource/Paris -- Name http://dbpedia.org/page/Paris -- Descriptor Resource (HTML+RDFa) this resource will expose other representations via head/ (link/ + @rel) or Link: in response headers etc.. Not sure what you are trying to say here. I must be misunderstanding because you appear to be claiming that http://dbpedia.org/resource/Paris is a name but http://dbpedia.org/page/Paris is a resource. Assuming you are using angle brackets like they are used in Turtle then I think they are both resources. I would say: http://dbpedia.org/resource/Paris -- a resource named by the string http://dbpedia.org/resource/Paris; http://dbpedia.org/page/Paris -- a resource named by the string http://dbpedia.org/page/Paris; Also, in my view the first resource is actually the city of paris whereas the second is a document about the first resource. I don't really see what relevance this all has to the issue of 303 redirection though. We are all agreed that things are not usually their own descriptions, we are discussing how that knowledge should be conveyed using Linked Data. Ironically, bearing in mind my comments, we do arrive at the same conclusion, but in different ways. I phrase my conclusion as: heuristics for implementing HTTP based Entity Names that Resolve to structured Descriptor Resources shouldn't dominate the Linked Data narrative, especially as comprehension of the fundamental concept remains mercurial. So are you contradicting your answer at the start of the post? Huh? I am saying, what I've already stated: heuristics re. essence of Linked Data mechanics shouldn't front the conversation. You sort of arrive there too, but we differ re. mandates. See my comment above: I am removing them from the front. Potential point of reconciliation: You assumed that 303 is an existing mandate. I am totally unaware of any such mandate. See above. I don't even buy into HTTP scheme based Names as a mandate, they simply make the most sense courtesy of Web ubiquity. As is already the case re., LINK
Re: Is 303 really necessary?
On Thu, Nov 4, 2010 at 3:21 PM, Giovanni Tummarello giovanni.tummare...@deri.org wrote: Hi Ian no its not needed see this discussion http://lists.w3.org/Archives/Public/semantic-web/2007Jul/0086.html pointing to 203 406 or thers.. ..but a number of social community mechanisms will activate if you bring this up, ranging from russian style you're being antipatriotic criticizing the existing status quo to ..but its so deployed now and .. you're distracting the community from other more important issues , none of this will make sense if analized by proper logical means of course (e.g. by a proper IT manager in a proper company, paid based on actual results). Yes, but I guess I have to face those to make progress. But the core of the matter really is : who cares. My educated guess looking at Sindice flowing data is that everyday out of 100 new sites on web of data 99.9 simply use RDFa which doesnt have this issue. I think it's an orthogonal issue to the one RDFa solves. How should I use RDFa to respond to requests to http://iandavis.com/id/me which is a URI that denotes me? choose how to publish yourself but here is another one. If you chose NOT to use RDFa you will miss out on anything which will enhance the user experience based on annotations. As an example see our entry in the semantic web challange [1]. I'm agnostic on formats, just trying to make things simpler for publishers who want to use hashless URIs in their data. Ian Giovanni [1] http://www.cs.vu.nl/~pmika/swc/submissions/swc2010_submission_19.pdf On Thu, Nov 4, 2010 at 2:22 PM, Ian Davis m...@iandavis.com wrote: Hi all, The subject of this email is the title of a blog post I wrote last night questioning whether we actually need to continue with the 303 redirect approach for Linked Data. My suggestion is that replacing it with a 200 is in practice harmless and that nothing actually breaks on the web. Please take a moment to read it if you are interested. http://iand.posterous.com/is-303-really-necessary Cheers, Ian
Re: Is 303 really necessary?
On Thu, Nov 4, 2010 at 3:50 PM, Giovanni Tummarello giovanni.tummare...@deri.org wrote: I think it's an orthogonal issue to the one RDFa solves. How should I use RDFa to respond to requests to http://iandavis.com/id/me which is a URI that denotes me? hashless? mm one could be to return HTML + RDFa describing yourself. add a triple saying http://iandavis.com/id/me containstriplesonlyabouttheresourceandnoneaboutitselfasinformationresource Yes, that's basically what I'm saying in my blog post. its up to clients to really care about the distinction, i personally know of no useful clients for the web of data that will visibly misbehave if a person is mistaken for a page.. so your you can certify to your customer your solution works well with any client Good to know. That's my sense too. if one will come up which operates usefully on both people and pages and would benefit from making your distinction than those coding that client will definitely learn about your containstriplesonlyabouttheresourceandnoneaboutitselfasinformationresource and support it. how about this ? :-) Sounds good to me :) as an alternative the post i pointed you earlier (the one about 203 406) did actually contain an answer i believe. 406 is perfect IMO .. I'd say a client which will care to make the distinction would learn to support it as in my previous example. I'll look into that. Ian
Re: Is 303 really necessary?
On Thu, Nov 4, 2010 at 3:56 PM, Kingsley Idehen kide...@openlinksw.com wrote: I don't presume. I prefer to use terms that are familiar with the people on this list who might be reading the message. Introducing unnecessary capitalised phrases distracts from the message. Again, you presume. Capitalization might not work for you, but you are not the equivalent of an entire mailing list audience. You are one individual entitled to a personal opinion and preferences. I hope you agree i have the freedom to express those opinions. Anyway, translation: What's the problem with having a variety of methods for using LINKs to associate a Non Information Resource with an Information Resource that describes it (i.e., carries its structured representation)? Why place an implementation detail at the front of the Linked Data narrative? It's already at the front, and as I say in my post it's an impediment to using Linked Data by mainstream developers. I don't believe its already at the front. I can understand if there was some quasi mandate that put it at the front. Again, you are jumping to conclusions, then pivoting off the conclusions to make a point. IMHO: Net effect, Linked Data concept murkiness and distraction. You are inadvertently perpetuating a misconception. Thank you for your opinion. I don't believe I am jumping to conclusions. There is. I find it surprising that you're unaware of it because it's in all the primary documents about publishing Linked Data. Please provide a URL for the document that establishes this mandate. I know of no such document. Of course I am aware of documents that offer suggestions and best practice style guidelines. Here is one cited by Leigh just now: http://www.w3.org/TR/cooluris/ Also http://lists.w3.org/Archives/Public/www-tag/2005Jun/0039.html And http://www4.wiwiss.fu-berlin.de/bizer/pub/LinkedDataTutorial/ The only thing that should be mandatory re. Linked Data is this: HTTP based Entity Names should Resolve to structured Descriptors that are Human and/or Machine decipherable. Are you saying that requesting a URI should return a description document? Resolve to a Descriptor Document which may exist in a variety of formats. Likewise, Descriptor documents (RDF docs, for instance) should clearly identify their Subject(s) via HTTP URI based Names. Example (in this example we have 1:1 re. Entity Name and Descriptor for sake of simplicity): http://dbpedia.org/resource/Paris -- Name http://dbpedia.org/page/Paris -- Descriptor Resource (HTML+RDFa) this resource will expose other representations viahead/ (link/ + @rel) or Link: in response headers etc.. Not sure what you are trying to say here. I must be misunderstanding because you appear to be claiming that http://dbpedia.org/resource/Paris is a name but That is a Name via HTTP URI (using its Name aspect). This is an interesting distinction between the resource and a name. Can you restate it in a new thread so we don't add noise to the 303 discussion I don't really see what relevance this all has to the issue of 303 redirection though. We are all agreed that things are not usually their own descriptions, we are discussing how that knowledge should be conveyed using Linked Data. Of course, my comments are irrelevant, off topic. If that works for you, then good for you. You spent all this time debating an irrelevance. That looks like a natural close to this particular part of the debate then. FWIW - 303 is an implementation detail, RDF is an implementation detail, and so is SPARQL. When you front line any conversation about the concept of Linked Data with any of the aforementioned, you are only going to make the core concept incomprehensible. Ian
Re: Is 303 really necessary?
On Thu, Nov 4, 2010 at 4:17 PM, Kingsley Idehen kide...@openlinksw.com wrote: On 11/4/10 11:50 AM, Giovanni Tummarello wrote: its up to clients to really care about the distinction, i personally know of no useful clients for the web of data that will visibly misbehave if a person is mistaken for a page.. so your you can certify to your customer your solution works well with any client Gio, Keyword: visibly. Once the Web of Linked Data crystallizes, smart agents will emerge and start roaming etc.. These agents need precision, so ambiguity will cause problems. At this point there will be broader context for these matters. Please don't dismiss this matter, things are going to change quickly, we live in exponential times. If the success of these agents is predicated on precision then they are doomed to failure. The web is a messy place but it's precisely that messiness that allows it to scale. Anyone building serious web data apps is used to dealing with ambiguity all the time and has strategies for compensating. Linked Data offers a route to higher precision, but in no way is it a panacea or silver bullet. Ian
Re: Is 303 really necessary?
On Thu, Nov 4, 2010 at 4:52 PM, Robin YANG yang.squ...@gmail.com wrote: Ok, yes, we can use ontology or ex:isDescribedBy, but none of solution explained what happens when you dereferencing the URI over HTTP which you just used to refer to the non-information resources. Don't u need 303 or hash URI again to differentiate when dereferencing whatever subject URI we minted before ex:isDescribedBy. When you dereference the URI you get back a representation with some data about the thing the URI denotes. I don't think you need any other URI unless you also want to assign a URI to the representation itself. Ian
Re: Is 303 really necessary?
Hi Dave, On Thu, Nov 4, 2010 at 4:56 PM, David Wood da...@3roundstones.com wrote: Hi all, This is a horrible idea, for the following reasons (in my opinion and suitably caveated): - Some small number of people and organizations need to provide back-links on the Web since the Web doesn't have them. 303s provide a generic mechanism for that to occur. URL curation is a useful and proper activity on the Web, again in my opinion. The relationship between 303 redirection and backlinks isn't clear to me. Can you expand? - Overloading the use of 200 (OK) for metadata creates an additional ambiguity in that the address of a resource is now conflated with the address of a resource described by metadata. My post addresses that case. I don't encourage people to use the same URI for both the metadata and the thing but to link them using a new predicate ex:isDescribedBy. I also say that you should believe the data. If the data says the thing you dereferenced is a document then that's what you should assume it is. If it says it's a toucan then that's what it is. - W3C TAG findings such as http-range-14 are really very difficult to overcome socially. Maybe so, but I don't think that should stop 5 years of deployment experience from informing a change of practice. This isn't really relevant to my main question though: what breaks on the web. - Wide-spread mishandling of HTTP content negotiation makes it difficult if not impossible to rely upon. Until we can get browser vendors and server vendors to handle content negotiation in a reasonable way, reliance on it is not a realistic option. That means that there needs to be an out-of-band mechanism to disambiguate physical, virtual and conceptual resources on the Web. 303s plus http-range-14 provide enough flexibility to do that; I'm not convinced that overloading 200 does. My proposal isn't dependent on conneg. You can use it with the same caveats as anywhere else. But the simple case is just to serve up some RDF at the URI being dereferenced. BTW, conneg is very widely deployed in the Linked Data web and doesn't seem to have been a problem. /me ducks for the inevitable mud slinging this list has become. We can improve the quality of discussion on this list. Regards, Dave Ian
Re: Is 303 really necessary?
On Thursday, November 4, 2010, Nathan nat...@webr3.org wrote:
Please, don't.
303 is a PITA, and it has detrimental affects across the board from network
load through to server admin. Likewise #frag URIs have there own set of PITA
features (although they are nicer on the network and servers).
However, and very critically (if you can get more critical than critical!),
both of these patterns / constraints are here to ensure that different
things have different names, and without that distinction our data is junk.
I agree with this and I address it in my blog post where I say we
should link the thing to its description using a triple rather than a
network response code.
This goes beyond your and my personal opinions, or those of anybody here, the
constraints are there so that in X months time when multi-corp trawls the
web, analyses it and releases billions of statements saying like { /foo
:hasFormat x; sioc:about dbpedia:Whatever } about each doc on the web, that
all of those statements are said about documents, and not about you or I, or
anything else real, that they are said about the right thing, the correct
name is used.
I don't see that as a problem. It's an error because it's not what the
original publisher intended but there are many many examples where
that happens in bulk, and actually the 303 redirect doesn't prevent it
happening with naive crawlers.
If someone asserts something we don't have to assume it is
automatically true. We can get authority about what a URI denotes by
dereferencng it. We trust third party statements as much or as little
as we desire.
And this is critically important, to ensure that in X years time when
somebody downloads the RDF of 2010 in a big *TB sized archive and considers
the graph of RDF triples, in order to make sense of some parts of it for
something important, that the data they have isn't just unreasonable junk.
Any decent reasoner at that scale will be able to reject triples that
appear to contradict one another. Seeing properties such as format
against a URI that everyone else claims denotes an animal is going to
stick out.
It's not about what we say something is, it's about what others say the thing
is, and if you 200 OK the URIs you currently 303, then it will be said that
you are a document, as simple as that. Saying you are a document isn't the
killer, it's the hundreds of other statements said along side that which make
things so ambiguous that the info is useless.
That's only true under the httpRange-14 finding which I am proposing
is part of the problem.
If 303s are killing you then use fragment URIs, if you refuse to use
fragments for whatever reason then use something new like tdb:'s, support the
data you've published in one pattern, or archive it and remove it from the
web.
These are publishing alternatives, but I'm focussed on the 303 issue here.
But, for whatever reasons, we've made our choices, each has pro's and cons,
and we have to live with them - different things have different name, and the
giant global graph is usable. Please, keep it that way.
Agree, different things have different names, that's why I emphasise
it in the blog post. I don't agree that the status quo is the best
state of affairs.
Best,
Nathan
Ian
Re: Is 303 really necessary?
On Thu, Nov 4, 2010 at 6:08 PM, Nathan nat...@webr3.org wrote: You see it's not about what we say, it's about what other say, and if 10 huge corps analyse the web and spit out billions of triples saying that anything 200 OK'd is a document, then at the end when we consider the RDF graph of triples, all we're going to see is one statement saying something is a nonInformationResource and a hundred others saying it's a document and describing what it's about together with it's format and so on. I honestly can't see how anything could reason over a graph that looked like that. I honestly believe that's the least of our worries. How often do you need to determine whether something in the universe of discourse is an electronic document or not compared with all the other questions you might be asking of your data. I might conceivable ask show me all the documents about this toucan but I'd much rather ask show me all the data about this toucan However, I'm also very aware that this all may be moot any ways, because many crawlers and HTTP agents just treat HTTP like a big black box, they don't know there ever was a 303 and don't know what the end URI is (even major browser vendors like chrome do this, setting the base wrong and everything) - so even the current 303 pattern doesn't keep different things with different names for /slash URIs in all cases. That's true. I don't suppose any of the big crawlers care about the semantics of 303 because none of them care about the difference between a thing and its description. For example the Google OpenSocial doesn't give a hoot about the difference and yet seems to still function. As I say above, this document/thing distinction is actually quite small area to focus on compared with the the real problems of analysing the web of data as a whole. Best, Nathan Ian
Re: Is 303 really necessary?
On Thursday, November 4, 2010, Jörn Hees j_h...@cs.uni-kl.de wrote: Hi Ian, From your blogpost: Under my new scheme: GET /toucan responds with 200 and a representation containing some RDF which includes the triples /toucan ex:owner /anna and /toucan ex:isDescribedBy /doc GET /doc responds with 200 and a representation containing some RDF which includes the triple /doc ex:owner /fred So how can I then say that your description of toucan is wrong without saying that the poor toucan is wrong? Use the URI of the document /doc Jörn Ian
Re: Please allow JS access to Ontologies and LOD
On Sat, Oct 23, 2010 at 2:28 AM, Nathan nat...@webr3.org wrote: Hi Ian, Thanks, I can confirm the change has been successful :) However, one small note is that the conneg URIs such as http://productdb.org/gtin/00319980033520 do not expose the header, thus can't be used. Ta. These should be emitting the header now. Ian
Re: Please allow JS access to Ontologies and LOD
Hi Nathan, I implemented this header on http://productdb.org/ (since I had the code open). Can someone comfirm that it does what's expected (i.e. allows off-domain requesting of data from productdb.org) One important thing to note. The PHP snippet you gave was slightly wrong. The correct form is: header(Access-Control-Allow-Origin: *); Cheers, Ian On Sat, Oct 23, 2010 at 12:04 AM, Nathan nat...@webr3.org wrote: Hi All, Currently nearly all the web of linked data is blocked from access via client side scripts (javascript) due to CORS [1] being implemented in the major browsers. Whilst this is important for all data, there are many of you reading this who have it in your power to expose huge chunks of the RDF on the web to JS clients, if you manage any of the common ontologies or anything in the LOD cloud diagram, please do take a few minutes from your day to expose the single http header needed. Long story short, to allow js clients to access our open data we need to add one small HTTP Response header which will allow HEAD/GET and POST requests - the header is: Access-Control-Allow-Origin * This is both XMLHttpRequest (W3C) and XDomainRequest (Microsoft) compatible and supported by all the major browser vendors. Instructions for common servers follow: If you're on Apache then you can send this header by simply adding the following line to a .htaccess file in the dir you want to expose (probably site-root): Header add Access-Control-Allow-Origin * For NGINX: add_header Access-Control-Allow-Origin *; see: http://wiki.nginx.org/NginxHttpHeadersModule For IIS see: http://technet.microsoft.com/en-us/library/cc753133(WS.10).aspx In PHP you add the following line before any output has been sent from the server with: header(Access-Control-Allow-Origin, *); For anything else you'll need to check the relevant docs I'm afraid. Best TIA, Nathan [1] http://dev.w3.org/2006/waf/access-control/
Re: Linked Data Movie Quiz
Guillermo, This is a very nice demo, well done! Is the architecture generic enough to apply to other datasets? Musicbrainz would be a good one once the new linked data version is ready. Cheers, Ian 2010/10/17 Guillermo Álvaro Rey galv...@isoco.com: Dear LODers, We have created a simple webapp that generates questions about cinema by querying the Linked Movie DataBase ([1], many thanks to Oktie et al. for that project and their support). The so-called Linked Data Movie Quiz is available at [2], as part of a contest where webapps had to be developed in less than 10KB [3]. We hope that even if simple, and not accessing but a single repository, the application is able to showcase the power of using available Linked Data. (Indeed, a huge number of questions are automatically generated with very little code.) Doing well in the contest proved difficult, for there were very nice HTML5 demos in there, but I reckon it was good in terms of Linked Data evangelism. :-) (I tried to write during the contest, but somehow the email didn't make it through.) There are some more details about the LDMQ in [4]. We'll be glad if you try it out (advice: less bugs -but still some- if you don't use IE6 or 7) and send some feedback. Cheers, Guillermo (and Jorge) [1] http://www.linkedmdb.org/ [2] http://10k.aneventapart.com/Uploads/310/ [3] http://10k.aneventapart.com/Entry/310 [4] http://lamboratory.com/blog/2010/08/25/a-linked-data-movie-quiz-the-answers-are-out-there-and-so-are-the-questions/ -- Guillermo Álvaro Rey Researcher galv...@isoco.com #T +34 91 334 97 43 Edificio Testa - Avda. del Partenón 16-18, 1º, 7ª Campo de las Naciones 28042 MADRID iSOCO enabling the networked economy www.isoco.com P Please consider your environmental responsibility before printing this e-mail
Re: PUBLINK Linked Data Consultancy
On Thu, Oct 7, 2010 at 1:00 PM, Michael Schneider schn...@fzi.de wrote: Sören Auer wrote: PS: Please also keep in mind that PUBLINK is very limited (max. 3-5 data owning organizations) and ca. 10 man days of support for each. I think those numbers are the really important bits. I have seen EU projects where there were plans to perform really huge field studies. I would consider this a problem in this case (not only for existing startups, but also for the project consortium :)). But 3-5 organizations sounds fair to me and will probably not lead to much conflict with existing companies. Whether 10 man days will be sufficient is a different question... :) While, I welcome more free assistance to linked data adoption, I think this would be most effective if it were targetted towards organisations that do not have existing funds to pay for training and consultancy. At Talis we have encountered several in that situation and while we help where we can we do have to earn an income. EU funded help would be perfect for these organisations. Targetting organisations that would otherwise buy from a commercial company just undermines a nascent market. Ian
Re: WordNet RDF
On Wed, Sep 8, 2010 at 12:39 PM, Toby Inkster t...@g5n.co.uk wrote: Dear all, I've created a think RDF wrapper around the WordNet 3.0 database (nouns only). For example: http://ontologi.es/WordNet/data/Fool Great work. There is a SPARQL'able version of Wordnet 3.0 available via the Talis Platform: http://api.talis.com/stores/wordnet This is based on the RDF conversion at http://semanticweb.cs.vu.nl/lod/wn30/ How similar is your work to this version? Ian
Re: [ANN] Major update of Lexvo.org
Hi Bernard, On Wed, Jul 7, 2010 at 2:04 PM, Bernard Vatant bernard.vat...@mondeca.com wrote: Basically that's it. If this practice seems good from social and technical viewpoint it could be a good idea to document it in a more formal way and put it somewhare on the wiki. There has been a page set up on the wiki a while ago about this issue, sorry can't find now the page address and who set it up, and I can't access now to http://community.linkeddata.org/MediaWiki/ for some reasons. This looks like a really good and sensible social process and I'd support it being more public on the wiki. Also, if anyone has datasets that they feel they cannot maintain any more, please consider using the Talis Connected Commons Scheme. We will host any public domain linked data for free for ever (or at least for as long as Talis exists which is 40 years so far). This is really a no-hassle solution with no strings whatsoever, just the commitment that the data is in the public domain for everyone's reuse. We are also looking to automatically deposit such datasets with the internet archive in the future. Please have a look at http://www.talis.com/platform/cc/ for more information on this scheme. Ian Looking forward for the feedback Bernard 2010/7/5 Gerard de Melo gdem...@mpi-inf.mpg.de Hi everyone, We'd like to announce a major update of Lexvo.org [1], a site that brings information about languages, words, characters, and other human language- related entities to the LOD cloud. Lexvo.org adds a new perspective to the Web of Data by exposing how everything in our world is connected in terms of language, e.g. via words and names and their semantic relationships. Lexvo.org first went live in 2008 just in time for that year's ISWC. Recently, the site has undergone a major revamp, with plenty of help from Bernard Vatant, who has decided to redirect lingvoj.org's language URIs to the corresponding Lexvo.org ones. At this point, the site is no longer considered to be in beta testing, and we invite you to take a closer look. On the front page, you'll find links to examples that will allow you get a feel for the type of information being offered. We'd love to hear your comments. Best, Gerard [1] http://www.lexvo.org/ -- Gerard de Melodem...@mpi-inf.mpg.de Max Planck Institute for Informatics http://www.mpi-inf.mpg.de/~gdemelo/ -- Bernard Vatant Senior Consultant Vocabulary Data Engineering Tel: +33 (0) 971 488 459 Mail: bernard.vat...@mondeca.com Mondeca 3, cité Nollez 75018 Paris France Web: http://www.mondeca.com Blog: http://mondeca.wordpress.com
Re: RDF Extensibility
2010/7/6 Dan Brickley dan...@danbri.org: 2010/7/6 Jiří Procházka oji...@gmail.com: It would have a meaning. It would just be a false statement. The same as the following is a false statement: foaf:Person a rdf:Property . Why do you think so? I believe it is valid RDF and even valid under RDFS semantic extension. Maybe OWL says something about disjointness of RDF properties and classes URI can be many things. It just so happens as a fact in the world, that the thing called foaf:Person isn't a property. It's a class. I think that is your view and the view you have codified as the authoritative definition that I can look up at that URI, but there is nothing preventing me from making any assertion I like and working with that in my own environment. If it's useful to me to say foaf:Person a rdf:Property then I can just do that. However, I shouldn't expect that assertion to interoperate with other people's views of the world. Ian
Re: Show me the money - (was Subjects as Literals)
On Fri, Jul 2, 2010 at 4:44 AM, Pat Hayes pha...@ihmc.us wrote: Jeremy, your argument is perfectly sound from your company's POV, but not from a broader perspective. Of course, any change will incur costs by those who have based their assumptions upon no change happening. Your company took a risk, apparently. IMO it was a bad risk, as you could have implemented a better inference engine if you had allowed literal subjects internally in the first place, but whatever. But that is not an argument for there to be no further change for the rest of the world and for all future time. Who knows what financial opportunities might become possible when this change is made, opportunities which have not even been contemplated until now? I think Jeremy speaks for most vendors that have made an investment in the RDF stack. In my opinion the time for this kind of low level change was back in 2000/2001 not after ten years of investment and deployment. Right now the focus is rightly on adoption and fiddling with the fundamentals will scare off the early majority for another 5 years. You are right that we took a risk on a technology and made our investment accordingly, but it was a qualified risk because many of us also took membership of the W3C to have influence over the technology direction. I would prefer to see this kind of effort put into n3 as a general logic expression system and superset of RDF that perhaps we can move towards once we have achieved mainstream with the core data expression in RDF. I'd like to see 5 or 6 alternative and interoperable n3 implementations in use to iron out the problems, just like we have with RDF engines (I can name 10+ and know of no interop issues between them) Ian
Re: destabilizing core technologies: was Re: An RDF wishlist
Patrick, Without disputing your wider point that HTML hit the sweet point of usability and utility I will dispute the following: HTML 3.2 did have: 1) *A need perceived by users as needing to be met* Did users really know they wanted to link documents together to form a world wide web? I spent much of the late nineties persuading companies and individuals of the merits of being part of this new web thing and then gritting my teeth when it came to actually showing them how to get a page online - it was a painful confusion of text editors ( no you can't use wordperfect ), fumbling in the dark ( no wysiwyg ), dialup ( you mean I have to pay?) and ftp! When MS frontpage came along the users loved it because all that pain went away but they could not understand why so many people laughed at the results. I think we all have short memories. The advantage that HTML had was that people were able to use it before creating their own, i.e. they were aleady reading websites so could at some point say I want to make one of those. The problem RDF is gradually overcoming is this bootstrapping stage. It has a harder time because, to be frank, data is dull. But now people are seeing some of the data being made available in browseable form e.g. at data.gov.uk or dbpedia and saying, I want to make one of those. Ian
Re: Show me the money - (was Subjects as Literals)
On Fri, Jul 2, 2010 at 10:19 AM, Patrick Durusau patr...@durusau.net wrote: I make this point in another post this morning but is your argument that investment by vendors = I think I just answered it there, before reading this message. Let me know if not! Ian Ian
Re: Subjects as Literals, [was Re: The Ordered List Ontology]
Yves, On Fri, Jul 2, 2010 at 10:15 AM, Yves Raimond yves.raim...@gmail.com wrote: First: this is *not* a dirty hack. Brickley bif:contains ckley is a perfectly valid thing to say. You could, today, use data: URIs to represent literals with no change to any RDF system. Ian
Re: Subjects as Literals, [was Re: The Ordered List Ontology]
On Fri, Jul 2, 2010 at 8:34 PM, Jeremy Carroll jer...@topquadrant.com wrote: On 7/2/2010 12:00 PM, Dan Brickley wrote: Or maybe we should all just take a weekend break, mull things over for a couple of days, and start fresh on monday? That's my plan anyhow... Yeah, maybe some of us could meet up in some sunny place and sit in an office, maybe at Stanford - just like last weekend! I have to say that meeting was a lot more civilised than the current raging debate on these lists! Jeremy Ian
Re: Organization ontology
On Tue, Jun 1, 2010 at 8:50 AM, Dave Reynolds dave.e.reyno...@googlemail.com wrote: We would like to announce the availability of an ontology for description of organizational structures including government organizations. Congratulations on the publication of this ontology! I've added it to Schemapedia here: http://schemapedia.com/schemas/org I noticed a small semantic typo in the example at the end of section 3. skos:preferredLabel should be skos:prefLabel Ian
ANNOUNCE: lod-announce list
Hi all, Now we are getting a steady growth in the number of Linked Data sites, products and services I thought it was time to create a low-volume announce list for Linked Data related announcements so people can keep up to date without needing to wade through the LOD discussion. You can join the list at http://groups.google.com/group/lod-announce Here is its summary: A low-traffic, moderated list for announcements about Linked Open Data and only for announcements. On topic messages include announcements of new Linked Data sites, data dumps, services, vocabularies, books, talks, products, tools, events, jobs and conferences with a Linked Data programme. You don't need to join the list to post to it, but all posts are moderated to ensure they stay on-topic. Please feel free to forward this message to other lists that you think might be relevant. Cheers, Ian PS Let me know if you are interested in being a moderator too.
Re: Linking a vCard to its holder
Hi you could use http://open.vocab.org/terms/businessCard There is also a proposal to add a similar property to FOAF at http://wiki.foaf-project.org/w/term_businessCard On Fri, May 14, 2010 at 1:32 PM, Felix Ostrowski felix.ostrow...@googlemail.com wrote: Hi, vCards in RDF seem to be a good way to describe people and organizations with regards to address information etc. Is there any convention to link a vCard to the person or organization it describes (i.e. its holder), e.g. http://example.org/me/vcard ?vCardOf? http://example.org/me or http://example.org/me ?hasvCard? http://example.org/me/vcard So far, I couldn't find an established predicate that does so... Cheers, Felix P.S. I find the examples at http://www.w3.org/Submission/vcard-rdf/#Ex to be rather misleading. v:VCard rdf:about = http://example.com/me/corky; ... /v:VCard is not an assertion I'd make about myself. I am not a vCard.
Re: Cross site scripting: CORS and a Javascript library accessing Linked Data
Hi Nathan, On Mon, May 10, 2010 at 10:49 PM, Nathan nat...@webr3.org wrote: Could everybody publishing linked data please note that open data isn't currently retrievable via client side JS libraries due to same origin policies and the likes. In order to make it open and accessible by UAs we need to add in CORS [1] headers. Just to be slightly pedantic, this is only a problem for applications running inside web browser sandbox contexts. Standalone apps, dedicated semweb browsers, iPhone apps, greasemonkey scripts etc don't suffer this limitation. That said, we are looking at CORS for support by Talis with the caveat that it is still not a REC stage and we prefer to implement agreed standards rather than ones in progress unless we're very confident they won't change. Ian
Re: DBpedia hosting burden
On Wed, Apr 14, 2010 at 8:04 PM, Dan Brickley dan...@danbri.org wrote: Bills the major operative word in a world where the Bill Payer and Database Maintainer is a footnote (at best) re. perception of what constitutes the DBpedia Project. If dbpedia.org linked to the sparql endpoints of mirrors then that would be a way of sharing the burden. Ian
Re: UK Govt RDF Data Sets
Kingsley, You should address your question directly to the project organisers, we're a technology provider and host some of the data but it is not up to us when or where the dumps get shared. My understanding is that because this is officially sanctioned data they want to ensure that the provenance is built into the datasets properly. My hope and wish is that the commitment to making dumps available will be built into the guidelines the UK Government are working on. But those won't be issued during this month because of the election. Ian On Thu, Apr 15, 2010 at 11:19 PM, Kingsley Idehen kide...@openlinksw.com wrote: Ian, While on the subject of mirrors and Linked Open Data in general. Do you have any idea as to the whereabouts of RDF data sets for the SPARQL endpoints associated with data.gov.uk? As you can imagine, I haven't opted to crawl your endpoints for the data bearing in LOD community ethos i.e., publish dataset dump locations for SPARQL endpoints that host Linked Open Data. This best practice was devised SPARQL endpoint crawling in mind. Example: http://data.gov.uk/sparql Where would I get the actual RDF datasets loaded into the endpoint above? Here is the RPI example re. data.gov: http://data-gov.tw.rpi.edu/wiki/Data.gov_Catalog_-_Complete . -- Regards, Kingsley Idehen President CEO OpenLink Software Web: http://www.openlinksw.com Weblog: http://www.openlinksw.com/blog/~kidehen Twitter/Identi.ca: kidehen
Re: UK Govt RDF Data Sets
On Fri, Apr 16, 2010 at 12:09 AM, Kingsley Idehen kide...@openlinksw.com wrote: Ian Davis wrote: Kingsley, You should address your question directly to the project organisers, we're a technology provider and host some of the data but it is not up to us when or where the dumps get shared. My understanding is that because this is officially sanctioned data they want to ensure that the provenance is built into the datasets properly. My hope and wish is that the commitment to making dumps available will be built into the guidelines the UK Government are working on. But those won't be issued during this month because of the election. Okay, but the need for dumps is working its way into the fundamental guidelines for Linked Open Data. As you can imagine (and I have raised these concerns on the UK Govt mailing list a few times), this project is high profile and closely associated with Linked Open Data; thus, unclarity about these RDF dumps is confusing to say the very least. Anyway, I am set for now, will wait and see re. what happens post election etc.. I should also add that some datasets do not have dumps, e.g. the reference time and dates http://reference.data.gov.uk/doc/hour/2010-03-23T21 Ian
Re: Announce: Linked Data Patterns book
On Wed, Apr 7, 2010 at 12:14 AM, Peter Ansell ansell.pe...@gmail.com wrote: In the Annotation publishing pattern section there is the following statement: It is entirely consistent with the Linked Data principles to make statements about third-party resources. I don't believe that to be true, simply because, unless users are always using a quad model (RDF+NamedGraphs), they have no way of retrieving that information just by resolving the foreign identifier which is the subject of the RDF triple. They would have to stumble on the information by knowing to retrieve the object URI, which isn't clear from the pattern description so far. In a triples model it is harmful to have this pattern as Linked Data, as the statements are not discoverable just knowing the URI. Can you elaborate more on the harm you suggest here? I don't think we need to limit the data published about a subject to that subset retrievable at its URI. (I wrote a little about this last year at http://blog.iandavis.com/2009/10/more-than-the-minimum ) I also don't believe this requires the use of quads. I think it can be interlinked using rdfs:seeAlso. Ian
Re: Linking HTML pages and data
On Wed, Feb 17, 2010 at 2:01 AM, Kingsley Idehen kide...@openlinksw.com wrote: I really don't believe we achieve much via: link rel=primarytopic href=http://education.data.gov.uk/id/school/56; / primarytopic isn't an IANA registered type link. Yes, I know. Nor is foaf:primaytopic :) I think there's a good chance of getting wide adoption for rel=primarytopic as a pattern / microformat / whatever. Having that very simple relation would be a massive boost for cross-linking the document web with the data web, important enough to warrant a special case IMHO. If you absolutely need to use foaf then its better to qualify it: link rel=foaf:primarytopic href=http://education.data.gov.uk/id/school/56; / Yes, its a PITA for the average HTML user/developer, but being superficially simpler doesn't make it a valid long term solution. There is a standard in place for custom typed links re. link/. The two are not exclusive. In an RDFa environment, I would suggest using foaf:primaryTopic (note case too - too easy for developers to mis-type) Ian
Re: Linking HTML pages and data
On Tue, Feb 16, 2010 at 7:42 PM, Ed Summers e...@pobox.com wrote: I also agree w/ Kingsley that it would be neat to also have a link pattern that non-RDFa folks could use: link rel=http://xmlns.com/foaf/0.1/primaryTopic; href=http://dbpedia.org/resource/Mogwai_(band) title=Mogwai / I have been promoting the use of the simpler primarytopic rel value as a pattern for linking HTML pages to the things they are about. I don't think we need to complicate things with pseudo namespaces etc for HTML, just focus on something simple people can copy. You can see it in use on data.gov.uk: http://education.data.gov.uk/doc/school/56 contains: link rel=primarytopic href=http://education.data.gov.uk/id/school/56; / Ian
Re: Fresnel: State of the Art?
The Fresnel Path Language was submitted as a note to the W3C a while back: http://www.w3.org/2005/04/fresnel-info/fsl/ I implemented that in PHP as part of the moriarty library: http://code.google.com/p/moriarty/source/browse/trunk/graphpath.class.php I think FSL is very interesting (having looked at many path languages for RDF over the past 5 or 6 years) and I'd like to see more implementations. Ian On Mon, Feb 1, 2010 at 1:44 PM, Aldo Bucchi aldo.buc...@gmail.com wrote: Hi, I was looking at the current JFresnel codebase and the project seems to have little movement. I was wondering if this is the state of the art regarding Declarative Presentation Knowledge for RDF or have efforts moved elsewhere and I have missed it? Thanks! A -- Aldo Bucchi skype:aldo.bucchi http://www.univrz.com/ http://aldobucchi.com/ PRIVILEGED AND CONFIDENTIAL INFORMATION This message is only for the use of the individual or entity to which it is addressed and may contain information that is privileged and confidential. If you are not the intended recipient, please do not distribute or copy this communication, by e-mail or otherwise. Instead, please notify us immediately by return e-mail.
Re: PHP RDF fetching code
You may find something useful in my Moriarty project: http://code.google.com/p/moriarty/ It's geared towards the Talis Platform but there is a lot of code in there that has no dependencies on the platform, e.g.: http://code.google.com/p/moriarty/source/browse/trunk/httprequest.class.php some documentation for that class here: http://code.google.com/p/moriarty/wiki/HttpRequest Ian
Re: Contd: [pedantic-web] question about sioc / foaf usage
I assume you've noticed the dearth of RDF examples that include descriptions of RDF files that are distinct, but connected, to the file contents. People have been doing that for years using foaf:primaryTopic. See example at http://xmlns.com/foaf/spec/#term_PersonalProfileDocument and substitute URIs for the nodeIDs Ian
Re: Contd: [pedantic-web] question about sioc / foaf usage
On Mon, Nov 30, 2009 at 10:37 PM, Kingsley Idehen kide...@openlinksw.com wrote: If you lookup Linked Data from spaces associated with myself of OpenLink you will see use the aforementioned property re. missing relation. Also, you may also find out that few people added the missing triple to their RDF files after nudges from me. I hope I've made things clearer? I've read this thread and I don't understand the fuss. Some people aren't linking the document to the data it contains so we should encourage them to. Don't know why that is characterised as a debacle. Ian
Re: Contd: [pedantic-web] question about sioc / foaf usage
On Tue, Dec 1, 2009 at 12:02 AM, Peter Ansell ansell.pe...@gmail.com wrote: The necessary declaration of document as distinct, and yet necessary for the definition of data, and the necessity of different URI's for these two concepts, are fundamental sticking points for many people. Who is getting stuck on this point? Documents have URIs, as do the things documents might contain data about. If the HTTP web no longer existed (or the internet connection was temporarily down), the discussion about document versus data would be mute. Simple RDF Triple database queries, that do not rely on HTTP communication, have no necessary need to refer to the Document/Artifact. Only data would exist in the RDF triples (unless you deliberately blur the division using the notion of foaf:Document via foaf:primaryTopic for instance). Hence the debacle with saying that Document is a necessary element to understand and use RDF data linked together using resolvable HTTP URI's when to many it is just an artifact that doesn't influence, and shouldn't need to semantically interfere with, the data/information content that is actually being referenced. I disagree. Documents aren't HTTP artefacts: they exist happily on disks, printouts and in books. You can identify the medium (the data container in Kingsley's words) separately from the things it is describing (the data items). In fact it is usually necessary to do, and intuitive for most people who can distinguish the publisher of a book from the protaganist it describes. In the long term, I see it as introducing a permanent link from a semantic RDF (or other similar format) universe to the current document segregated web that wouldn't be there if everyone shared their RDF information through some other system, and for example only used the URI verbatim to do queries on some global hashtable/index somewhere where there was no concept of document at the native RDF level. The definition of Linked Data doesn't specifically say that HTTP URI's have to be resolved using HTTP GET requests over TCP port 80 using DNS for an intermediate host name lookup as necessary, so why should it require the notion of documents to be necessary containers for data pretty much just because that is how HTTP GET semantics work. I characterise it as a debacle because it has been a recurring discussion for many years and shows that the semantic communicty hasn't quite cleaned up its architecture/philosophy enough for it to be clear to people who are trying to understand it and utilise it without delving into philosophical debates. It seems pretty clear to me and many others in my experience, certainly not a debacle. Cheers, Peter Ian
Showcase of Linked Data at Online Information
Hi all, I am delivering a Semantic Web track keynote at Online Information this year( http://www.online-information.co.uk/ ) on the subject of The Reality of Linked Data. I want to showcase the work of the community in putting Linked Data to work and bringing real benefit to end users. I am looking for examples of live applications of the technology that go beyond toy or theoretical examples. I'm not really looking for examples of datasets unless they are demonstrating significant adoption outside of the core community (i.e. not dbpedia but bestbuy and the bbc are significant) If you are applying Linked Data please send me an outline of what you are doing, links to where I can see it and a screenshot you would like me to use (and are happy for me to put in the public domain as part of my slide deck). I will endeavour to include as many as I can in my talk. Best regards, Ian
Re: Top three levels of Dewey Decimal Classification published as linked data
On Mon, Aug 24, 2009 at 2:56 PM, Ross Singerrossfsin...@gmail.com wrote: Anyway, yes, I think some more thought needs to go into Dewey and LCSH's relationship to the real world. I think http://www.flickr.com/photos/danbri/3282565132 might be relevant here The classification that danbri uses in that diagram is quite interesting. I paraphrase them as: things, types, web documents (or information resources) and conceptualizations. I'm not attempting to define them at the moment. I tried to enumerate how these four categories interelate: things - things via general rdf properties things - types via rdf:type things - web documents via foaf:topic/foaf:isTopicOf/rdfs:seeAlso web documents - types via rdf:type, maybe via foaf:topic if the document is describing the type web documents - conceptualizations via dc:subject web documents - web documents via rdfs:seeAlso etc types - types via rdfs:subClassOf conceptualizations - conceptualizations via skos:broader/skos:narrower/etc. A couple were missing: For things - conceptualizations I recently created ov:category [1] and ov:isCategoryOf [2] which I used in productdb.org to link things with their categories (e.g. http://productdb.org/2006-honda-element). Using dc:subject didn't seem right - does a model of car have a subject? This is what I would suggest you use to relate an author to a category about them. The other one that is missing is types - conceptualization SKOS says there is no defined relationship [3]. Interestingly the RDF Semantics has this to say [4]: RDFS classes can be considered to be rather more than simple sets; they can be thought of as 'classifications' or 'concepts' which have a robust notion of identity which goes beyond a simple extensional correspondence. -Ross. Ian [1] http://open.vocab.org/terms/category [2] http://open.vocab.org/terms/isCategoryOf [3] http://www.w3.org/TR/skos-reference/#L896 [4] http://www.w3.org/TR/rdf-mt/#technote
Re: Top three levels of Dewey Decimal Classification published as linked data
On Wed, Aug 19, 2009 at 7:27 PM, Panzer,Michaelpanz...@oclc.org wrote: Hi all, I would like to announce the availability of the DDC Summaries as a linked data service that uses SKOS and other vocabularies for representation [1]. Please take a look if you like. Comments, suggestions, and advice are really appreciated! Very pleased to see this happen at OCLC and I hope there's more to come! Ian
Re: ProductDB
On Fri, Aug 14, 2009 at 10:47 AM, Toby Inkstert...@g5n.co.uk wrote: Does anyone know of any vocabs that provide terms like these? If not, shall I add to the VoCampBristol2009 todo list? Maybe my first ever RDF schema would be useful: http://vocab.org/barter/0.1/ Ian
Re: Distributed versioning for RDF?
Have you looked into changesets which is used by the Talis Platform? See http://n2.talis.com/wiki/Changesets and http://vocab.org/changeset/schema.html Ian On Wed, Jul 29, 2009 at 2:37 PM, Axel Rauschmayera...@rauschma.de wrote: Offhand, I see the following requirements for many (mostly social) RDF applications: - text indexing - text diff for versioning - distributed versioning and synchronization. http://en.wikipedia.org/wiki/Distributed_version_control - provenance: author, data source (which might have named graphs) Open Anzo [1] and OpenLink Data Spaces [2] come pretty close, but, as far as I can tell, don't offer distributed versioning. Is there anything else out there that I might have missed? Thanks! Axel [1] http://www.openanzo.org/ [2] http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/Ods -- Axel Rauschmayer a...@rauschma.de http://www.pst.ifi.lmu.de/people/staff/rauschmayer/axel-rauschmayer/ http://2ality.blogspot.com/ http://hypergraphs.de/
Linked Data and the Public Domain
I wrote up some background to licensing, waivers, the public domain and how it applies to linked data. I also included examples of how you can declare a public domain waiver for a linked dataset. http://blogs.talis.com/nodalities/2009/07/linked-data-public-domain.php Hope this helps people with these complex issues. In other news, our tutorial Legal and Social Frameworks for Sharing Data on the Web which covers these kinds of issues was accepted for ISWC2009. I am not a lawyer, but we will have an expert lawyer taking part in that tutorial (see http://www.jordanhatcher.com/ ) Ian
Re: [Ann] LinkedGeoData.org
On Wednesday, July 8, 2009, Sören Auer a...@informatik.uni-leipzig.de wrote: Dear Colleagues, On behalf of the AKSW research group [1] I'm pleased to announce the first public version of the LinkedGeoData.org datasets and services. LinkedGeoData is a comprehensive dataset derived from the OpenStreetMap database covering RDF descriptions of more than 350 million spatial features (i.e. nodes, ways, relations). LinkedGeoData currently comprises RDF dumps, Linked Data and REST interfaces, links to DBpedia as well as a prototypical user interface for linked-geo-data browsing and authoring. Very nice. How long do you think it will take for the entire dataset to be available? Open streetmap are voting soon on whether to adopt the open data commons sharealike database license. If they adopt it will you also adopt it for this data? Sören Auer Ian [1] http://aksw.org -- Sören Auer, AKSW/Computer Science Dept., University of Leipzig http://www.informatik.uni-leipzig.de/~auer, Skype: soerenauer
Re: .htaccess a major bottleneck to Semantic Web adoption / Was: Re: RDFa vs RDF/XML and content negotiation
On Wednesday, July 8, 2009, Toby Inkster t...@g5n.co.uk wrote: On Wed, 2009-07-08 at 15:13 +0100, Mark Birbeck wrote: The original point of this thread seemed to me to be saying that if .htaccess is the key to the semantic web, then it's never going to happen. It simply isn't the key to the semantic web though. .htaccess is a simple way to configure Apache to do interesting things. It happens to give you a lot of power in deciding how requests for URLs should be translated into responses of data. If you have hosting which allows you such advanced control over your settings, and you can create nicer URLs, then by all means do so - and not just for RDF, but for all your URLs. It's a Good Thing to do, and in my opinion, worth switching hosts to achieve. But all that isn't necessary to publish linked data. If you own example.com, you can upload foaf.rdf and give yourself a URI like: http://example.com/foaf.rdf#alice (Or foaf.ttl, foaf.xhtml, whatever.) This just works and is how the html web grew. Write a document and save it into a publuc spaxe. Fancy stuff like pretty URIs need more work but are not at all necessary for linked data or the semantic web. Let's not blow this all out of proportion. Hear hear! -- Toby A Inkster mailto:m...@tobyinkster.co.uk http://tobyinkster.co.uk
Re: LOD Data Sets, Licensing, and AWS
On Wed, Jun 24, 2009 at 4:05 PM, Kingsley Idehen kide...@openlinksw.comwrote: My comments are still fundamentally about my preference for CC-BY-SA. Hence the transcopyright reference :-) I want Linked Data to have its GPL equivalent; a license scheme that: Have you read the licenses at http://opendatacommons.org/ ? Ian
The Public Domain (was Re: LOD Data Sets, Licensing, and AWS)
On Wed, Jun 24, 2009 at 9:56 PM, Kingsley Idehen kide...@openlinksw.comwrote: The NYT, London Times, and others of this ilk, are more likely to contribute their quality data to the LOD cloud if they know there is a vehicle (e.g., a license scheme) that ensures their HTTP URIs are protected i.e., always accessible to user agents at the data representation (HTML, XML, N3, RDF/XML, Turtle etc..) level; thereby ensuring citation and attribution requirements are honored. I agree with that, but it only covers a small portion of what is needed. You fail to consider the situations where people publish data about other people's URIs, as reviews or annotation. The foaf:primaryTopic mechanism isn't strong enough if the publisher requires full attribution for use of their data. If I use SPARQL to extract a subset of reviews to display on my site then in all likelihood I have lost that linkage with the publishing document. Attribution is the kind of thing one gives as the result of a license requirement in exchange for permission to copy. In the academic world for journal articles this doesn't come into play at all, since there is no copying (in the usual case). Instead people cite articles because the norms of their community demand it. Yes, and the HTTP URI ultimately delivers the kind mechanism I believe most traditional media companies seek (as stated above). They ultimately want people to use their data with low cost citation and attribution intrinsic to the medium of value exchange. The BBC is a traditional media company. Its data is licensed only for personal, non-commercial use: http://www.bbc.co.uk/terms/#3 btw - how are you dealing with this matter re. the nuerocommons.org linked data space? How do you ensure your valuable work is fully credited as it bubbles up the value chain? I found this linked from the RDF Distribution page on neurocommons.org : http://svn.neurocommons.org/svn/trunk/product/bundles/frontend/nsparql/NOTICES.txt Everyone should read it right now to appreciate the complexity of aggregating data from many sources when they all have idiosyncratic requirements of attribution. Then read http://sciencecommons.org/projects/publishing/open-access-data-protocol/ to see how we should be approaching the licensing of data. It explains in detail the motivations for things like CC-0 and PDDL which seek to promote open access for all by removing restrictions: Thus, to facilitate data integration and open access data sharing, any implementation of this protocol MUST waive all rights necessary for data extraction and re-use (including copyright, sui generis database rights, claims of unfair competition, implied contracts, and other legal rights), and MUST NOT apply any obligations on the user of the data or database such as “copyleft” or “share alike”, or even the legal requirement to provide attribution. Any implementation SHOULD define a non-legally binding set of citation norms in clear, lay-readable language. Science Commons have spent a lot of time and resources to come to this conclusion, and they tried all kinds of alternatives such as attribution and share alike licences (as did Talis). The final consensus was that the public domain was the only mechanism that could scale for the future. Without this kind of approach, aggregating, querying and reusing the web of data will become impossibly complex. This is a key motivation for Talis starting the Connected Commons programme ( http://www.talis.com/platform/cc/ ). We want to see more data that is unambiguously reusable because it has been placed in the public domain using CC-0 or the Open Data Commons PDDL. So, I urge everyone publishing data onto the linked data web to consider waiving all rights over it using one of the licenses above. As Kingsley points out, you will always be attributed via the URIs you mint. Ian PS. This was the subject of my keynote at code4lib 2009 If you love something, set it free, which you can view here http://www.slideshare.net/iandavis/code4lib2009-keynote-1073812
Re: LOD Data Sets, Licensing, and AWS
Hi all, On Tue, Jun 23, 2009 at 9:36 PM, Kingsley Idehen kide...@openlinksw.comwrote: All, As you may have noticed, AWS still haven't made the LOD cloud data sets -- that I submitted eons ago -- public. Basically, the hold-up comes down to discomfort with the lack of license clarity re. some of the data sets. Action items for all data set publishers: 1. Integrate your data set licensing into your data set (for LOD I would expect CC-BY-SA to be the norm) Please do not use CC-BY-SA for LOD - it is not an appropriate licence and it is making the problem worse. That licence uses copyright which does not hold for factual information. Please use an Open Data Commons license or CC-0 http://www.opendatacommons.org/licenses/ http://wiki.creativecommons.org/CC0 If your dataset contains copyrighted material too (e.g. reviews) and you hold the rights over that content then you should also apply a standard copyright licence. So for completeness you need a licence for your data and one for your content. If you use CC-0 you can apply it to both at the same time. Obviously if you aren't the rightsholder (e.g. it is scraped data/content from someone else) then you can't just slap any licence you like on it - you have to abide by the original rightsholder's wishes. Personally I would try and select a public domain waiver or dedication, not one that requires attributon. The reason can be seen at http://en.wikipedia.org/wiki/BSD_license#UC_Berkeley_advertising_clausewhere stacking of attributions becomes a huge burden. Having datasets require attribution will negate one of the linked data web's greatest strengths: the simplicity of remixing and reusing data. A group of us have submitted a tutorial on these issues for ISWC 2009, hopefully it will get accepted because this is a really important area of Linked Data that is poorly understood. 2. Indicate license terms in the appropriate column at: http://esw.w3.org/topic/DataSetRDFDumps If licenses aren't clear I will have to exclude offending data sets from the AWS publication effort. I completely support declaring what rights are asserted or waived for a dataset, so please everyone help this effort. Ian
Re: http://ld2sd.deri.org/lod-ng-tutorial/
On Tue, Jun 23, 2009 at 8:01 AM, Giovanni Tummarello g.tummare...@gmail.com wrote: Just a remark about what we're doing in Sindice, for all who want to be indexed properly by us. we recursively dereference the properties that are used thus trying to obtain a closure over the description of the properties that are used. We also consider OWL imports. When the recursive fetching is computer, we apply RDFS + some owl reasoning (OWLIM being the final reasoner at the moment) and index it. Just out of interest, if you detect an inconsistency do you still index it? Ian
Re: http://ld2sd.deri.org/lod-ng-tutorial/
On Tue, Jun 23, 2009 at 10:12 AM, Dan Brickley dan...@danbri.org wrote: On 23/6/09 11:01, Martin Hepp (UniBW) wrote: And Michael, please be frank - there is a tendency in the LOD community which goes along the lines of OWL and DL-minded SW research has proven obsolete anyway, so we LOD guys and girls just pick and use the bits and pieces we like and don't care about the rest. What made the Web so powerful is that its Architecture is extremely well-thought underneath the first cover of simplicity. One of those principles is partial understanding - the ability to do something useful without understanding everything... Absolutely. We should also remember that multiple ontologies may exist that cover a given term. I think this is often forgotten. There is no requirement that the ontology statements retrieved by dereferencing the URI should be used - they are only provided as _an_ additional source of information. There may be many other ways to discover relevant ontologies and a large class of those will be for private use. If I choose to assert that dc:date and rev:createdOn are owl:equivalentProperties then that is my prerogative. The beauty of the semweb is that I can publish my assertions and potentially other people could choose to adopt them. Ian
Re: LOD Data Sets, Licensing, and AWS
On Tue, Jun 23, 2009 at 11:11 PM, Kingsley Idehen kide...@openlinksw.comwrote: Using licensing to ensure the data providers URIs are always preserved delivers low cost and implicit attribution. This is what I believe CC-BY-SA delivers. There is nothing wrong with granular attribution if compliance is low cost. Personally, I think we are on the verge of an Attribution Economy, and said economy will encourage contributions from a plethora of high quality data providers (esp. from the tradition media realm). Regardless of any attribution economy, CC-BY-SA is basically unenforceable for data so is not appropriate. You can't copyright the diameter of the moon. Ian
Re: LOD Data Sets, Licensing, and AWS
On Wednesday, June 24, 2009, Peter Ansell ansell.pe...@gmail.com wrote: 2009/6/24 Ian Davis li...@iandavis.com On Tue, Jun 23, 2009 at 11:11 PM, Kingsley Idehen kide...@openlinksw.com wrote: Using licensing to ensure the data providers URIs are always preserved delivers low cost and implicit attribution. This is what I believe CC-BY-SA delivers. There is nothing wrong with granular attribution if compliance is low cost. Personally, I think we are on the verge of an Attribution Economy, and said economy will encourage contributions from a plethora of high quality data providers (esp. from the tradition media realm). Regardless of any attribution economy, CC-BY-SA is basically unenforceable for data so is not appropriate. You can't copyright the diameter of the moon. Ian Interestingly, there is a large economy involved with patenting gene sequences. Aren't they facts also? Why is patenting different to copyright in this respect? I can't explain the technicalities (IANAL) but there are many different types of property rights that are granted by governments over information : copyright, database right, patent right, moral right etc. Each of those have seperate legislation that varies by jurisdiction (WIPO is attempting to normalising some of them). It's complicated which is why the efforts of creative commons, science commons and open data commons are so valuable: they create simple ways for people to declare the conditions under which their data and content can be reused. Ian
Re: gimmee some data!
On Mon, Jun 15, 2009 at 10:14 AM, Toby Inkster t...@g5n.co.uk wrote: On Mon, 2009-06-15 at 01:03 +0100, Hugh Glaser wrote: On 15/06/2009 00:18, Toby A Inkster t...@g5n.co.uk wrote: I still need to add some 303 redirects in there. Better hurry up, people might find it... http://sameas.org/html?uri=http://ontologi.es/place/GB-WAR Cool! Thanks you very much. I hope this is the start of a trend and that we all get birthday data! :) It was late, so I was cutting corners, but it's tidied up now, plus an index with voiD description has been added at http://ontologi.es/place/ Aside: http://unlocode.rkbexplorer.com/id/GBAFT should have label Alfriston (with an l) - perhaps an error in the source data? I noticed a slight encoding error on http://ontologi.es/place/http://ontologi.es/place/GB-WAR I think you have unescaped ampersands in there. Cheers, Ian
Re: gimmee some data!
Wow! Thank you, I'm reallly speechless. Best birthday present ever :) On Sunday, June 14, 2009, Hugh Glaser h...@ecs.soton.ac.uk wrote: What a fun idea I thought - more fool me? We should be able to do that pretty easily, shouldn't we? So I went and looked in the reference section of Project Gutenberg, and chose a book (A Short Biographical Dictionary of English Literature by John W. Cousin). However, several hours later, I am not pleased with the result, but really need to get back to my marking (yes, it was a bit of a displacement activity :-) ), and it may be enough for someone else to polish. Anyway, Happy Birthday!, a brand new present: http://biolit.rkbexplorer.com/ Hugh On 14/06/2009 10:23, Danny Ayers danny.ay...@gmail.com wrote: It's Ian Davis' birthday tomorrow, and for it he wants some linked data. So what datasets does anyone know of that can be translated relatively quick easy, the stuff you are planning to do one day when you get time..? -- http://danny.ayers.name
Re: Common Tag - semantic tagging convention
Congratulations! This looks really good On Thursday, June 11, 2009, Andraz Tori and...@zemanta.com wrote: Hi guys, today, a small consortium of web companies and one institute (AdaptiveBlue, DERI (NUI Galway), Faviki, Freebase, Yahoo!, Zemanta, and Zigtag) released a format specifying expression of semantic tags so our tools will understand/publish them. http://commontag.org It is RDFa based and it does not mandate specific vocabulary of meanings for tags. DBpedia and Freebase are currently used by Zigtag, Faviki and Zemanta. Soon Glue browsing extension will support it too - so there's going to be improved browsing experience as a bonus for semantically tagging the content. We tried to build on previous experience of MOAT and others and simplify even further, so the barrier to entry will be low as possible (but still RDFa is not grokked by a lot of publishing platforms). I am interested on your thoughts in this! And if anyone wants to use this somewhere please report it, so we'll put it under Applications page at http://commontag.org [i'll be traveling in next few days and won't be able to answer emails promptly, but there are guys from other organizations this list that will] -- Andraz Tori, CTO Zemanta Ltd, New York, London, Ljubljana www.zemanta.com mail: and...@zemanta.com tel: +386 41 515 767 twitter: andraz, skype: minmax_test
Re: Linked Data upcoming Semantic Technologies 2009 Conference.
I'd like to attend but that wiki page appears to be locked for edits, so I can't add myself. Can you add me? On Tue, Jun 9, 2009 at 6:21 PM, Kingsley Idehen kide...@openlinksw.comwrote: All, If you're attending the Semantic Web Technologies 2009 Conference in San Jose, note that there will be a Linked Data meetup [1]. I also have a 30 minute slot covering the use of Linked Data to solve real problems [2], I hope to use Linked Data to expand the 30 minute window :-) I am also part of a Linked Data discussion panel [3] (moderated by: Paul Miller) that includes Leigh Dodds, Jamie Taylor, and others. Links: 1. http://esw.w3.org/topic/SweoIG/TaskForces/CommunityProjects/LinkingOpenData/SanJoseGathering 2. http://semtech2009.com/session/2012/ 3. http://semtech2009.com/session/1988/ -- Regards, Kingsley Idehen Weblog: http://www.openlinksw.com/blog/~kidehenhttp://www.openlinksw.com/blog/%7Ekidehen President CEO OpenLink Software Web: http://www.openlinksw.com
Re: New github project for RDFizer scripts
On Thu, May 21, 2009 at 7:53 PM, Kingsley Idehen kide...@openlinksw.comwrote: All, The 30+ xslt stylesheets [1]used by the our collection Sponger Cartridges are now available for community development and enhancement via a github [2]. Links: 1. http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/ClickableVirtSpongerCloud 2. http://tr.im/m0PT Very nice :) I hope people start to feed back and make them even more useful Ian
Re: [ANN] Linking Open Data Triplification Challenge 2009
On Sat, May 16, 2009 at 10:03 AM, Michael Hausenblas michael.hausenb...@deri.org wrote: With the recent uptake of structured data/RDF by major players such as Google the motivation for exposing relational data and other structured data sources on the Web entered a new stage. We encourage participants to publish existing structured (relational) representations, which are already backing most of the existing Web sites and demonstrate useful and usable applications on top of it. Entrants for the competition might find the Talis Connected Commons scheme useful. It provides free hosting and services such as full text search, faceting and sparql for public domain datasets up to 50 million triples. See http://www.talis.com/platform/cc/ for details Ian
Commercial Product Announcements
Hi all, I'm not aware of any official policy on commercial posts to this list, but usual mailing list etiquette generally recommends that postings about commercial services and products should indicate their nature and give some indication of cost. I think this is even more important when the mailing list is focussed on a project with an open or free theme. Obviously, as I represent a vendor my preference is to allow commercial postings but I would also prefer that they are clearly labelled as such. Is this a policy that other members would like to see made explicit? Ian
Re: Domain and range are useful Re: DBpedia 3.2 release, including DBpedia Ontology and RDF links to Freebase
On Tue, Nov 18, 2008 at 4:02 AM, Tim Berners-Lee [EMAIL PROTECTED] wrote: On 2008-11 -17, at 11:27, John Goodwin wrote: [...] I'd be tempted to generalise or just remove the domain/range restrictions. Any thoughts? There are lots of uses for rand and domain. One is in the user interface -- if you for example link a a person and a document, the system can prompt you for a relationship which will include is author of and made but won't include foaf:knows or is issue of. Similarly, when making a friend, one can us autocompletion on labels which the current session knows about and simplify it by for example removing all documents from a list of candidate foaf:knows friends. Both these use cases require some OWL to say that documents aren't people. I don't see these scenarios being feasible in the general case because you'd need a complete description of the world in OWL, i.e. you'd want to know about everything that can't possibly be a person. It is of course also important for checking hand-written files for validity. Again, isn't validity checking something that can only be done with OWL. RDFS only adds for information. Tim BL Ian
Re: New LOD Cloud - Please send us links to missing data sources
I wonder if we could highlight those doing a great job in this space more, e.g. I believe Opera's foaf output is LOD On Fri, Sep 19, 2008 at 1:45 PM, Tom Heath [EMAIL PROTECTED] wrote: Sad but true. Things are improving in my experience but we still have some evangelism to do in this area. On 19/09/2008, [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: but by that token you could probably wipe out most of foaf and doap space from the diagram Most of that data is not very linky and many primary resources being described don't have uris On 9/19/08, Tom Heath [EMAIL PROTECTED] wrote: Hey Mischa, Good to hear you :) Just to add to what Peter said, last time I checked LiveJournal was not very Linked Data-friendly, which is a shame, naturally, as they were well ahead of the curve with the FOAF export. Cheers, Tom. 2008/9/19 Peter Ansell [EMAIL PROTECTED]: - [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: From: [EMAIL PROTECTED] [EMAIL PROTECTED] To: public-lod@w3.org Sent: Friday, September 19, 2008 1:55:07 AM GMT +10:00 Brisbane Subject: Re: New LOD Cloud - Please send us links to missing data sources Hello, There doesnt seem to be any mention of the LiveJournal or any of the livejournal powered blogging sites, such as: vox, friendfeed, hi5 to name a few. I think they are implicitly in the FOAF cloud, for want of a better description of that node ;) Cheers, Peter Find out more about Talis at www.talis.com Shared InnovationTM Any views or personal opinions expressed within this email may not be those of Talis Information Ltd. The content of this email message and any files that may be attached are confidential, and for the usage of the intended recipient only. If you are not the intended recipient, then please return this message to the sender and delete it. Any use of this e-mail by an unauthorised recipient is prohibited. Talis Information Ltd is a member of the Talis Group of companies and is registered in England No 3638278 with its registered office at Knights Court, Solihull Parkway, Birmingham Business Park, B37 7YB. __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __ Find out more about Talis at www.talis.com Shared InnovationTM Any views or personal opinions expressed within this email may not be those of Talis Information Ltd. The content of this email message and any files that may be attached are confidential, and for the usage of the intended recipient only. If you are not the intended recipient, then please return this message to the sender and delete it. Any use of this e-mail by an unauthorised recipient is prohibited. Talis Information Ltd is a member of the Talis Group of companies and is registered in England No 3638278 with its registered office at Knights Court, Solihull Parkway, Birmingham Business Park, B37 7YB. __ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email __
Job Advert: Linked Data Developer
== Linked Data Developer == Our platform development group is responsible for making sure that the Talis Platform is the premier environment for developing and delivering great Semantic Web applications. We need your help to convert and generate Linked Data sets for use by these and other applications. We're looking for people who: * use their code to communicate their ideas clearly * are experts in scripting and automating data conversions * have been involved in open source or community projects * can devise new strategies for processing data at scale * never forget about scalability, performance and security * prefer to develop test first * are proficient at modeling data in RDF * have an opinion on httpRange-14 * aren't afraid to ask questions * like to say let's try it and we can do that * understand how to balance perfection with reality * are as happy to lead as to follow * know when to reuse and when to start afresh * can tell us about something new they learned this year == How to apply == Take a look at the problems below and select two to answer. Please send us your C.V and an application letter telling us about yourself and including your answers to [EMAIL PROTECTED] Talis is based in Birmingham, UK but this role is amenable to remote working so we welcome non-UK applicants. 1. Describe how you would model the cast list of a movie as Linked Data. How would your approach cope if one cast member wanted higher billing on movie posters? Discuss the trade-offs involved in modeling lists and collections in RDF paying particular attention to how the data can be optimized for wide reuse. 2. Give an example of how you have automated long running processes in the past and some of the issues you encountered. What strategies would you adopt for coping with failures in the process and its environment? 3. Discuss your approach to producing Linked Data in domains that have no pre-existing consensus on the model or vocabulary. How would you ensure the data is immediately usable by as many interested parties as possible while retaining the ability to evolve the model? Additionally, how would you then build consensus in the community around the chosen model?
