Agenda - Semantic Web Deployment WG face-to-face

8-9 October, Amsterdam

This draft agenda: http://www.w3.org/2006/07/SWD/wiki/AmsterdamAgenda
Registration: http://www.w3.org/2002/09/wbs/39408/swd-ftf-adam-registration/
Agenda and logistics: http://www.few.vu.nl/~aisaac/swd/
Remote participation (telecon) info
Expected:
- WG members: Tom, Guus, Diego, Ed, Justin, Antoine, Jon, Alistair, Sean
- Guests: Steven Pemberton (RDFa), Mark Birbeck (RDFa), Ivan Herman
- By irc/telecon: Elisa, Ben, Michael, Simone, Daniel, Ralph

Meeting packet

2007-10-08 Monday

9:00-13:00 (0700 - 1000 UTC)
- RDFa
14:00-18:00 (1100 - 1600 UTC)
- SKOS: Labeling properties (Alistair) - Tom chairs
- SKOS: Semantic relation properties (Sean)
- 16:00 Vocabulary Management (Vit, with Elisa remotely)
- 17:00 Review of Cool URIs (Michael remotely)

2007-10-09 Tuesday

AM
- SKOS Concept semantics (Antoine)
- SKOS Label relations (Guus)
- SKOS: Drawing the picture (all)
PM
- Recipes (Jon)

RDFa (Mark Birbeck, 3 hours)

Required reading
- RDFa Primer
- XHTML1.1 RDFa Syntax
PROPOSAL: that the SWD WG agree to bring the following RDFa documents to REC track:
- XHTML1.1 RDFa Syntax
PROPOSAL: that the SWD WG approve publication of RDFa-in-XHTML-1.1 Syntax as a first Public Working Draft
PROPOSAL: that the SWD WG approve publication of a new Public Working Draft of the RDFa-in-XHTML-1.1 Primer.
PROPOSAL: that the RDFa Primer be finalized as a Note over the next few months
PROPOSAL: that the RDFa Use Cases: Scenarios for Embedding RDF in HTML (editor's draft of 2007-03-23) (working draft of 2007-03-30) be finalized as a Note over the next few months
PROPOSAL: that the Test Cases be used as supporting documentation for the syntax (not part of the REC track package):

SKOS

General reading

Three central issues (Alistair, 2007-06-26 posting)

'''Issue-31 - BasicLexicalLabelSemantics''' (open): defining the semantics of the three basic labelling properties, skos:prefLabel, skos:altLabel and skos:hiddenLabel -- see Topic "Labeling Properties" (Alistair)
'''Issue-44 - BroaderNarrowerSemantics''' (open): defining the semantics of skos:broader and skos:narrower -- see Topic "Semantic Relation Properties" (Sean)
'''Issue-54 ConceptSemantics''' (open): defining the semantics of skos:Concept -- see Topic "Concept Semantics" (Antoine)

"Labeling properties" (Alistair)

Background information and discussion for this topic is given in the following document:

http://purl.org/net/skos/2007/10/f2f/labelling-properties.html

This document is required reading, along with the SKOS Core Guide (section: Labelling Properties) and the SKOS Core Vocabulary Specification (only sections skos:prefLabel, skos:altLabel and skos:hiddenLabel).

Some notes and simplified decision points are at /SkosLabellingProperties.

"Semantic Relation Properties" (Sean)

What are the semantics of skos:broader and skos:narrower? There are several open questions:

Are they transitive/intransitive?
Are they reflexive/irreflexive?
Is the transitive closure irreflexive (i.e. a cycle is a contradiction)?

The transitivity of the relationships could be enshrined in the vocabulary, e.g. through making skos:broader and skos:narrower instances of owl:transitiveProperty. Or we can say nothing and leave it up to applications to decide whether to treat the relationships as transitive. Specific vocabularies may also be able to define transitive subproperties of broader/narrower if required.

Similarly for reflexivity, although this requires expressivity outside of OWL (but which is in the proposed OWL 1.1 spec).

Questions to consider:

Which use cases exhibit a necessity for transitive broader/narrower?
If the relationships are transitive, what impact does this have on presentations? For example, hierarchical views may want to only show "direct" broader terms, as is the case with most tools and sub/superclass relationships.
Do we expect interaction between skos:related and skos:broader/narrower. For example, if x related y and y broader z, do we expect x related z? Again, such functionality is now supported in OWL 1.1 extensions.

Potential solutions:

Say nothing about characteristics of broader/narrower.
Include characteristics of broader/narrower.

Relevant issues:

'''Issue-44 - BroaderNarrowerSemantics''' (open)

Background reading:

Related material:

Discussion about SKOS Validator

Alistair's strawman proposal for semantics of broader/narrower/related:

http://www.w3.org/2006/07/SWD/wiki/SkosDesign/SemanticRelations/MinimalProposal?action=recall&rev=6

"Concept Semantics" (Antoine)

Problems to discuss:

Defining the semantics of skos:Concept
Mixing with OWL concepts

Required reading:

ConceptSemantics - Antoine's issue summary

Relevant issues:

'''Issue-54 ConceptSemantics''' (open)

What are the semantics of skos:Concept?

skos:Concept is currently declared as { skos:Concept rdf:type rdfs:Class . } ... is this ok? Is this enough? What about the OWL universe?

Alistair's strawman proposal for semantics of skos:Concept:

http://www.w3.org/2006/07/SWD/wiki/SkosDesign/ConceptSemantics/MinimalProposal?action=recall&rev=3

Discussion from Alistair on interaction with major design patterns for working with SKOS and OWL:

http://purl.org/net/skos/2007/10/f2f/skos-owl-patterns.html

"Label relations" (Guus)

SKOS allows to represent semantic relationships (broader, related) between concepts. It also allows to represent relationships between concepts and labels (prefLabel, altLabel). However, there is nothing proposed in SKOS to capture links between labels themselves, a configuration which sometimes happens in concept schemes.

Relevant issues:

'''Issue-26 - RelationshipsBetweenLabels''' (open)
- Issue: SKOS allows to represent semantic relationships (broader, related) between concepts. It also allows to represent relationships between concepts and labels (prefLabel, altLabel). However, there is nothing proposed in SKOS to capture links between labels themselves, a configuration which sometimes happens in concept schemes.

Required background reading:

SkosDesign RelationshipsBetweenLabels

Three options will be discussed in Amsterdam

Discussion from Alistair on variations of the "Simple Extension" proposal:

http://purl.org/net/skos/2007/10/f2f/label-relations.html (see also [http://lists.w3.org/Archives/Public/public-swd-wg/2007Oct/0019.html Alistair's position on the options).

Drawing the picture (discussion leader?)

Problems to discuss:

Are relationships part of a concept scheme?
Are the concepts part of a concept scheme?
Capture underlying intuitions: UML diagrams? Blobs and lines?
What do we mean by "containment", "aggregation"...?
Are relationships of a concept somehow part of the concept?
Can concepts "exist" independently of a scheme?
Goal: see how things fit together in the larger picture.

Relevant issues:

ISSUE-36 http://www.w3.org/2006/07/SWD/track/issues/36 - ConceptSchemeContainment (open)
- Guus thoughts on ISSUE-36: http://lists.w3.org/Archives/Public/public-swd-wg/2007Jul/0164.html
- Alistair: http://www.w3.org/2006/07/SWD/wiki/SKOS/UserStories useful for ISSUE-36?

Alistair's strawman proposal for a semantics for skos:ConceptScheme:

http://www.w3.org/2006/07/SWD/wiki/SkosDesign/ConceptSchemes/MinimalProposal?action=recall&rev=1 (see also this email).

Vocabulary Management (Vit locally, Elisa remotely): 60 minutes

To be discussed late afternoon Monday 16:00+ so that Elisa can join.

Discussion points

VocabMgtDraft structure, section requirements, status (Elisa, 30 minutes)
Version management of ontologies (Vit, 30 minutes)
- Vit will present:
  - Versioning Questionnaire Evaluation - preliminary report on the results at [X]
  - Reference Implementation of RDF-based Ontology Versioning - SemVersion (partially funded by the Knowledge Web EU project); the tool description in a paper at [Y], the tool web site at [Z]
  - Versioning best practices based on early results of diff capabilities and multi-version ontology reasoning
- The WG should discuss which of this topics should be reflected in VocabMgtDraft (and how)

Required Reading

http://www.w3.org/2006/07/SWD/wiki/VocabMgtDraft

Recipes for publishing RDF vocabularies (Jon)

Required reading:
- Current list of issues: http://madcreek.com/w3c/swdwg_f2f_issues.html
- Draft of Recipe 6: http://www.w3.org/2006/07/SWD/wiki/BestPracticeRecipe6
Suggested reading:
- "How to publish linked data" tutorial by Bizer, Cyganiak and Heath: http://sites.wiwiss.fu-berlin.de/suhl/bizer/pub/LinkedDataTutorial/
- "Cool URIs for the Semantic Web": http://www.dfki.uni-kl.de/%7Esauermann/2006/11/cooluris/
- TAG finding: "Associating Resources with Namespaces": http://www.w3.org/2001/tag/doc/nsDocuments/
- Latest Working Draft (2006-03-14): http://www.w3.org/TR/swbp-vocab-pub/
Discussion points:
- Discuss and resolve an strategy to close ISSUE-58:
  - Should we fix the general case?
  - Is it enough to fix the most common cases?
- Discuss the current draft of Recipe 6: http://www.w3.org/2006/07/SWD/wiki/BestPracticeRecipe6
  - Do we have the time now, or will someone(s) volunteer to review?
- Briefly review status of issues 19 to 24:
  - ISSUE-19 http://www.w3.org/2006/07/SWD/track/issues/19 - Recipes should supply a general server configuration template (open)
    - Should the recipes supply this in order to better support non-Apache servers?
  - ISSUE-20 http://www.w3.org/2006/07/SWD/track/issues/20 - Online server testing (open) There's a sourceforge project: http://vapour.sourceforge.net/
    - If we develop a web interface for it, who can host it?
  - ISSUE-22 http://www.w3.org/2006/07/SWD/track/issues/22 - Questioning reference to 'IE6 hack' (open) in Content Negotiation section http://www.w3.org/TR/swbp-vocab-pub/#negotiation
    - Should we "remove from the document any suggestion that the reader should delete the directive and just insert an explanation as to why it's needed;"?
  - ISSUE-23 http://www.w3.org/2006/07/SWD/track/issues/23 - There should be some discussion of alternatives to .htaccess (open)
    - Should we do this?
- Discuss the relationship between the Recipes, current issues, and the more recently published 'Linked Data', 'Cool URIs', and 'Associating Resources' documents: http://sites.wiwiss.fu-berlin.de/suhl/bizer/pub/LinkedDataTutorial/, http://www.dfki.uni-kl.de/%7Esauermann/2006/11/cooluris/, http://www.w3.org/2001/tag/doc/nsDocuments/
  - Should we expand or revise the discussion of the content of documents returned by dereferencing a URI in the
    - minimum requirements: http://www.w3.org/TR/swbp-vocab-pub/#minimumrequirements
    - URI namespaces: http://www.w3.org/TR/swbp-vocab-pub/#naming
    - Appendix B. Vocabulary URIs based on a 303-redirect service: http://www.w3.org/TR/swbp-vocab-pub/#redirect
  - This discussion also impacts these issues...
    - ISSUE-24 http://www.w3.org/2006/07/SWD/track/issues/24 - Additional text explaining redirect choices in the recipes (open)
    - ISSUE-30 http://www.w3.org/2006/07/SWD/track/issues/30 - Determine how and if RDDL relates to the Recipes (raised)
    - ISSUE-60 http://www.w3.org/2006/07/SWD/track/issues/60 - Guidelines needed for proper construction of vocabulary scheme and 'term' URIs (raised)

Agenda - Semantic Web Deployment WG face-to-face

Meeting packet

2007-10-08 Monday

2007-10-09 Tuesday

RDFa (Mark Birbeck, 3 hours)

SKOS

"Labeling properties" (Alistair)

"Semantic Relation Properties" (Sean)

"Concept Semantics" (Antoine)

"Label relations" (Guus)

Drawing the picture (discussion leader?)

Vocabulary Management (Vit locally, Elisa remotely): 60 minutes

Recipes for publishing RDF vocabularies (Jon)

SKOS issues (as of 2007-08-21)

SKOS requirements (as of 2007-08-21)