Hi,
trying to understand the data and interaction model [1], the last two
teleconferences of the Working Group at W3C have done nothing but
confirm my suspicions: right now there are too many core decisions a bit
undefined or unclear. Since joining the WG not from the beginning could
be a problem to understand the background of some discussions, I'd like
to focus this as something constructive rather than destructive.
Therefore I'd like to discuss these issues with the Marmotta team,
specially Andy and Nandana who are also involved in the WG, before send
my questions to the mailing list.
Some key documents to read would be:
- LDP spec [2]
- LDP Uses Cases and Requirements [3]
- Composition vs. aggregation in LDPC (ISSUE-34 [4]) and a basic
proposal [5]
- Data and interaction model (ISSUE-37 [6]) and some proposals [7]
So here a list of my main questions:
- First of all, fmpov the goal is too high-level defined (see the
charter [8]), and this derives that it is hard to argue some key
decisions, which is being conflictive when trying to find agreements
with all members. Maybe my point of view is too close to my RWW
experience, but I guess the current protocol is just a meta-protocol
with some considerations.
- Unfortunately the use case and requirements do not address such issue.
I don't know where the user stories come from, but definitely the uses
cases do not cover the overall problem, I think, LDP will address. Maybe
we can take a look on this document with more detail and contribute
where we can clarify some details from the implementation point of view.
- Mixing the data model with the interaction model within a single
formalism is confusing. For instance I agree that LDPC could be a
subclass of LDPR, but I don't see where this benefits how to use the
protocol to interact.
- For instance, I'm still figuring how Marmotta could distinguish
between normal Linked Data resources and LDPR. I mean, we already
implement our Read Write Linked Data interpretation, and I see some
details which do not easily fit with a single endpoint implementation.
- There are three different perspectives of the same problem
(triple-oriented, resource-oriented and graph-oriented) somehow rubbing
between them. For instance, with the Graph Store Protocol in mind [9], I
clearly see LDPC as a kind of special graphs with some restrictions in
some properties, rather than a normal resource. But these limits or
details fmpov are not clear at all.
Additionally I know we have some valuable extensions to propose
(versioning and so on), but for the moment I'd prefer to keep it and try
to focus the work at the WG.
Thank so much.
Kind regards,
[1] https://issues.apache.org/jira/browse/MARMOTTA-21
[2] https://dvcs.w3.org/hg/ldpwg/raw-file/default/ldp.html
[3] https://dvcs.w3.org/hg/ldpwg/raw-file/default/ldp-ucr.html
[4] http://www.w3.org/2012/ldp/track/issues/34
[5] http://www.w3.org/2012/ldp/wiki/Issue-34:_Back_to_Basics
[6] http://www.w3.org/2012/ldp/track/issues/37
[7] http://www.w3.org/2012/ldp/wiki/ISSUE-37#Linked_Data_Platform
[8] http://www.w3.org/2012/ldp/charter
[9] http://www.w3.org/TR/sparql11-http-rdf-update/
--
Sergio Fernández
Salzburg Research
+43 662 2288 318
Jakob-Haringer Strasse 5/II
A-5020 Salzburg (Austria)
http://www.salzburgresearch.at
