RDF Data Shapes Working Group Teleconference

05 May 2016


See also: IRC log


Arnaud, hknublau, Dimitris, kcoyle, pfps, TallTed, marqh, jamsden
labra, ericP


<scribe> scribenick: dimitris


<Arnaud> PROPOSED: Approve minutes of the 28 April 2016 Telecon: http://www.w3.org/2016/04/28-shapes-minutes.html

arnaud: let's start, propose to approve minutes from last week

RESOLUTION: Approve minutes of the 28 April 2016 Telecon: http://www.w3.org/2016/04/28-shapes-minutes.html

Disposal of Raised Issues

<Arnaud> PROPOSED: Open ISSUE-158

<pfps> ISSUE-158

<trackbot> ISSUE-158 -- ill-typed literals do not always trigger a validation result -- raised

<trackbot> http://www.w3.org/2014/data-shapes/track/issues/158

<Arnaud> issue-158

<trackbot> issue-158 -- ill-typed literals do not always trigger a validation result -- raised

<trackbot> http://www.w3.org/2014/data-shapes/track/issues/158

<TallTed> +1


<pfps> fine by me to open 158

<hknublau> +1

<kcoyle> +1

<pfps> +1



<trackbot> issue-123 -- Shall we unify the syntax of sh:directType and sh:class? -- open

<trackbot> http://www.w3.org/2014/data-shapes/track/issues/123

<Arnaud> PROPOSED: Close ISSUE-123, dropping sh:directType

arnaud: we talked about this, it seems there is consensus to drop sh:directType

<hknublau> +1

<pfps> +1

<jamsden> +1


<marqh> +1

RESOLUTION: Close ISSUE-123, dropping sh:directType


<trackbot> issue-135 -- Should sh:and/sh:or/sh:not/sh:valueShape support constraints too? -- open

<trackbot> http://www.w3.org/2014/data-shapes/track/issues/135

<pfps> there have been several emails

arnaud: we talked about issue 135, people liked the idea for simplification and Holger sent an email with a proposal

hknublau: i noticed I made a mistake with the original proposal, I was propagating property constraints, the solution is simpler without changes but I am not ready for a complete proposal

<Arnaud> https://www.w3.org/2014/data-shapes/wiki/Proposals#ISSUE-135:_and.2For_syntactic_sugar

pfps: there is an nice proposal from Eric, if extended properly it could be a good candidate

arnaud: ericP is not here and cannot answer questions, maybe best is to give WG another week

Public comment

<kcoyle> second set of comments from

<kcoyle> Baker https://lists.w3.org/Archives/Public/public-rdf-shapes/2016May/0004.html

arnaud: there were some comments on the editors draft from Thomas Baker and we need to decide how to responde to these comments
... his seems quite knowledgable and his comments are very interesting
... some comments validate what we hear from Peter

pfps: he is confused about terminology, the interaction between shacl and rdfs and validation
... what I do not understand in his comments is the OWA in the shapes graph
... OWA and CWA have to do with logics but we need to make it clear so people not get confused

hknublau: we closed many of these points no need to reopen them again but there is editorial work to be done
... I am also open to find suitable terms, I am open to renaming

<pfps> I don't think that there is anything in Tom's comments that are not editorial. He is not asking for any changes in SHACL, or at least that is my interpretation of his comments.

arnaud: he is trying to get on board with what we are thiunking but it not very clear

tallted: 1) an editor's draft is not supposed to be consumed from people outside the group, they can look at the next public draft
... 2) reg OWA / CWA they do not apply in what we are doing

arnaud: what we could do is go through thoma's list

pfps: I think people looking at editor's draft are more to be treasured than those looking at the public draft

arnaud: we haven't published in several months and we are due on that

jamsden: let's treat his review like a review from a WG member

<Arnaud> https://lists.w3.org/Archives/Public/public-rdf-shapes/2016May/0000.html

arnaud: the first two points can set the expectations for the reader

pfps: constraint has many meanings, Karen also had problems with the term, we need a better introduction that doesn't include constraint

<jamsden> its not constraints on the graph, its constraints imposed by and application of or use of the graph for a purpose

arnaud: we have two levels of constraints, on a high level of constraining an RDF node with a shape and lower level constraints

jamsden: the word constraint is ok but we do not constrain the graph

kcoyle: we are not constraining we are validating
... we also have components which is confusing

arnaud: we have different use case and we can also constraint web forms

kcoyle: validation is most prominent

marqh: I want to highlight two words, one is "context and the other is "validate", the term validate is not easy to misinterpret

tallted: like other w3c specs we are overloading terms
... validation and constraint can mean the same or different things
... we got to be very clear on the definitions

pfps: every word we use has a meaning associated with it, we should try and use words that are as close as possible to what we want to say
... we either should be very careful when using the term constraint or avoid it. I agree with Karen, validate covers what we do
... why not get away from constraints?

marqh: point 1 in Tom's email is define constraint upfront
... we should also be consistent through out the spec

arnaud: let's go to point 2 "If a shape is described in RDF, say so early on"

pfps: I think there is confusion on the use of rdfs in the shapes graph

arnaud: is this rdf vs rdfs?

pfps: yes, shacl uses only the rdfs terms not the meaning

kcoyle: where does SHACL fit with W3c technology?

arnaud: the problem is with inferencing where we say we do not but sneak some in

<pfps> but what is RDF? is it RDF graphs? is it the old intuitive meaning of RDF graphs? is the the newer formal meaning of RDF graphs? and then what about RDFS?

tallted: classes and subclasses did not originate from RDF, even in biology we have these terms
... someone needs to suggest alternative terminology

marqh: reading section 1.3 can make people worry that something is wrong
... are we trying to be too defensive?
... can we say it in a slightly different way?

tallted: we always need to say there is no reasoning
... you have to do all your reasoning before

<kcoyle> three things: needs an application

marqh: I see a confusion on what is (a shapes graph) and what do I do with it
... can individuals respond to specific comments?

arnaud: I am open, we can certainly to ask for clarifications

pfps: that is not going to work
... otherwise we have N different people saying N different things
... there is a response that I do not completely agree with

arnaud: I have a suggestion, it could be ok for people to ask questions but not to give answers

pfps: email exchange can be very messy and we owe Tom a good response

tallted: we can have a WG delegate do it

arnaud: point 5 suggests we move the extension mechanism to another document

hknublau: this is an opinion of one person
... splitting this makes our job much harder

arnaud: the reason take this seriously is because it validates some comments we had in the WG

tallted: we should take this into consideration but it is only one comment

<hknublau> +1 to a primer if there are volunteers

kcoyle: is this an indication that a primer could be required as a document

arnaud: LDP does something similar

marqh: +1 for a primer document
... people who do not want to implement shacl do not need the whole specification

arnaud: the information is not still stable enough to have a test suite even a primer

kcoyle: I can help with the examples

SHACL Draft Publication

arnaud: we need to publish another public version of the draft

hknublau: I would like a resolution of datatype vs class before the next draft
... this would be the final syntax changes
... we also have a lot of editorial work

pfps: it would be nice to have an attempt to response to Tom before a public working draft

arnaud: we do not have time to answer all his points one by one before publishing the draft
... I will send a reply to him explaining this

<hknublau> @Dimitris, I'll delete sh:directType

<Arnaud> trackbot, end meeting

Summary of Action Items

Summary of Resolutions

  1. Approve minutes of the 28 April 2016 Telecon: http://www.w3.org/2016/04/28-shapes-minutes.html
  2. Open ISSUE-158
  3. Close ISSUE-123, dropping sh:directType
[End of minutes]

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$Date: 2016/05/13 16:44:07 $