To: CODE4LIB@LISTSERV.ND.EDU
Subject: Re: [CODE4LIB] Expressing negatives and similar in RDF
Jeremy,
This is the kind of thing that people are doing with SPARQL, and I think the
principle is the same although the technology is different. SPARQL has ways to
do negation in a query:
http://www.w3
for Libraries [mailto:CODE4LIB@LISTSERV.ND.EDU] On Behalf Of Karen
Coyle
Sent: Sunday, September 22, 2013 10:14 AM
To: CODE4LIB@LISTSERV.ND.EDU
Subject: Re: [CODE4LIB] Expressing negatives and similar in RDF
Steve, yes, you've nailed it, IMO.
There's a paper from some DERI folk that addresses
Sent: Sunday, September 22, 2013 10:14 AM
To: CODE4LIB@LISTSERV.ND.EDU
Subject: Re: [CODE4LIB] Expressing negatives and similar in RDF
Steve, yes, you've nailed it, IMO.
There's a paper from some DERI folk that addresses negations, and it's all so
complex that it does make one want to say
Isn't the issue here that it is very hard to break from the object/property
model into an RDF/assertion model [1]? It seems to me that the rare book
cataloger's assertion:
This book does not have a title
only looks like it should translate to
example:book1 dc:title someOntology:nil
because of
Steve, yes, you've nailed it, IMO.
There's a paper from some DERI folk that addresses negations, and it's
all so complex that it does make one want to say: fuggetaboudit. Here's
a snippet:
begin snippet
The semantics of RDF(S) is purely monotonic and described in terms of
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
I appreciate the time you're taking to unpack this point. I agree that it's
subtle and important.
Speaking of prescription and description, I suspect that we're talking past
each other along those lines. I understand you to be expositing the
Of
Karen Coyle
Sent: 16 September 2013 16:23
To: CODE4LIB@LISTSERV.ND.EDU
Subject: Re: [CODE4LIB] Expressing negatives and similar in RDF
On 9/16/13 2:05 AM, Meehan, Thomas wrote:
Don: As I understand it, the open world view implies knowledge not
asserted for whatever reason, whereas
I don't think anyone would want to use one ontology for all work, especially
not a public ontology. I can imagine people using ontology extensions that are
specific to the purpose of validation, and I've found them useful myself.
I'm not arguing against using SPARQL for validation. I do think
t.mee...@ucl.ac.uk
-Original Message-
From: Code for Libraries [mailto:CODE4LIB@LISTSERV.ND.EDU] On Behalf Of
Karen Coyle
Sent: 16 September 2013 16:23
To: CODE4LIB@LISTSERV.ND.EDU
Subject: Re: [CODE4LIB] Expressing negatives and similar in RDF
On 9/16/13 2:05 AM, Meehan, Thomas wrote:
Don
Agreed that SPARQL is ugly, and there was discussion at the RDF
validation workshop about the need for friendly interfaces that then
create the appropriate SPARQL queries in the background. This shouldn't
be surprising, since most business systems do not require users to write
raw SQL or even
Hi Tom,
I think it comes down to what you really mean by a book not having a
title. A few options I can think of:
1) This book was published without a title (or whatever verb you want
there if you want to cover unpublished material)
2) The author did not give this work a title
3) I've never
On 13/09/13 23:32, Meehan, Thomas wrote:
However, it would be more useful, and quite common at least in a bibliographic context, to say This book does not
have a title. Ideally (?!) there would be an ontology of concepts like none, unknown, or
even something, but unspecified:
This book has
Street
London WC1E 6BT
t.mee...@ucl.ac.uk
-Original Message-
From: Code for Libraries [mailto:CODE4LIB@LISTSERV.ND.EDU] On Behalf Of
Donald Brower
Sent: 13 September 2013 14:46
To: CODE4LIB@LISTSERV.ND.EDU
Subject: Re: [CODE4LIB] Expressing negatives and similar in RDF
2013 14:46
To: CODE4LIB@LISTSERV.ND.EDU
Subject: Re: [CODE4LIB] Expressing negatives and similar in RDF
At a theoretical level, doesn't the Open World Assumption in RDF rule out
outright negations? That is, someone else may know the title, and could
assert it in a separate RDF document. RDF
This reminds me of a conversation (that did not come to a conclusion) on
the BIBFRAME list about the need to have a way to say that a bit of data
is transcribed, not transcribed, or supplied. And that reminds me of the
issues with SKOS labels, which is that if your data is text, not a URI,
you
Hmm. For the missing title would you create a content as text node with
a blank body? How does RDF handle empty strings?!
(And I'm sorry to say that the qname for content as text is cnt - I'm
going to have to just get over the dis-ease that causes me )
kc
On 9/14/13 6:47 AM, Esmé Cowles
Yes, I was thinking you would create a content as text node, and just leave the
value blank (or maybe use something like rdf:nil).
And the good thing about qnames is that you can use whatever you want. I
always use mads: instead of madsrdf: for MADS, and would use cat: or
content: for content
This mentions empty strings but doesn't give an example of one:
*Lexical Space.* An rdf:PlainLiteral lexical form is a string of the
form /abc/@/langTag/ where /abc/ is an arbitrary (possibly empty)
string, and /langTag/ is either the empty string or a (not necessarily
lowercase) language
It's too bad rdf:nil is only for lists -- I think it could be handy in many
other contexts. But just using an empty string should be fine:
example:book1 dc:title _:bn1 .
_:bn1 rdf:type content:ContentAsText .
_:bn1 content:characterEncoding UTF-8 .
_:bn1 content:chars .
I'm not sure I got
Hello,
I'm not sure how sensible a question this is (it's certainly theoretical), but
it cropped up in relation to a rare books cataloguing discussion. Is there a
standard or accepted way to express negatives in RDF? This is best explained by
examples, expressed in mock-turtle:
If I want to
Thomas-
This isn't something I've run across yet. But one thing you could do is create
some URIs for different kinds of unknown/nonexistent titles:
example:book1 dc:title example:unknownTitle
example:book2 dc:title example:noTitle
etc.
You could then describe example:unknownTitle with a label
+1
On Fri, Sep 13, 2013 at 8:51 AM, Esmé Cowles escow...@ucsd.edu wrote:
Thomas-
This isn't something I've run across yet. But one thing you could do is
create some URIs for different kinds of unknown/nonexistent titles:
example:book1 dc:title example:unknownTitle
example:book2 dc:title
At a theoretical level, doesn't the Open World Assumption in RDF rule out
outright negations? That is, someone else may know the title, and could
assert it in a separate RDF document. RDF semantics seem to conflate
unknown with nonexistent.
Practically, Esme's approach seems better in these
On 9/13/13 5:51 AM, Esmé Cowles wrote:
Thomas-
This isn't something I've run across yet. But one thing you could do is create
some URIs for different kinds of unknown/nonexistent titles:
example:book1 dc:title example:unknownTitle
example:book2 dc:title example:noTitle
etc.
I'm bothered by
The MARC21 Authority format does have some negative assertions. Field 675
asserts that a source contains no relevant information (vs. 670 which
asserts the source and its relevant information). Field 673 asserts that a
title is not related to the entity in the 1XX (vs. 672 which asserts that
the
OWL contains some negative assertions, as Thomas noted. Nothing prevents
anyone else from negating your negative, however, in that Open World.
Assuming that we have provenance on statements, then you might be able
to make sense of two conflicting bits of information.
I've found two
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