W3C * Semantic Web Activity * WebOnt WG * Member Events

Jan 2002 Meeting of the Web Ontology Working Group

Hosted by Lucent Technologies in New Jersey, USA

Dan Connolly, team contact
Jim Hendler, chair
Created Jan 2002 from template
$Revision: 1.41 $ of $Date: 2002/02/04 14:41:52 $


See roll call below.

Also:3 Jan attendee list

Venue: Bell Labs, Murray Hill, New Jersey

Peter F. Patel-Schneider, is the local host; see local info, details

thanks to OpenProjects for #webont and to ILRT for IRC/log facilities.

Preparation: Drafts for Review

Drafts for discussion at this meeting are due 7 Jan 2002.. This allows us to make the best use of our time: folks can come to the meeting prepared, and nobody has reviewed the wrong version, etc.

In addition, it is recommended to review the Working Group Charter and the various background references from the working group web page.


per 31 Dec msg from the chair. Note the local logistics details, which call for meeting at "Stair 9" entrance at 8:30am.

Monday Jan 14

9:00 - 9:15 Welcome - Logistics overview, etc. Patel-Schneider/Hendler
9:15 - 10:00 Charter Review Hendler/Connolly

Discussion of WOWG Goals, what is projected to be produced what is out of charter, etc.

Discussion of what to call the language (WOL, SWOL, OWL)

10:00 - 10:30 BREAK
10:30 - 12:00 DAML+OIL Technical Detail Ian Horrocks

Detailed review of DAML+OIL language; presentation of advanced features not discussed in walkthru

12:00 - 13:00 Lunch
13:00 - 15:00 Use Case Discussion I Schreiber, Obrst, Decker, Heflin/McGuinness

Presentation/Discussion of use cases

15:00 - 15:30 break
15:30 - 17:00 SWOL Discussion Peter Patel-Schneider

Presentation of suggested changes

EVENING: Dinner and/or Social gathering (TBD) Relaxed opportunity to meet/mingle

Tuesday, Jan 15

9:00 - 10:00 DAML+OIL Use Review TDB

Presentation/Discussion of how D+O has been used in the past, and potential impacts on our Web Ontology langauge

10:00 - 10:30 break
10:30 - 12:00 Break-out Session I

Use case focus - meet in groups to discuss the use case areas and on document

12:00 - 13:00 Lunch
13:00 - 14:30 Break-out Session II

Compiling requirements

Hot topics (Swol, Daml use, etc.)

14:30 - 15:00 break
15:00 - 17:00 Discussion/Planning Hendler

Discussion of next steps for group Determination of calendar for next f2fs

Review of Action Items assigned during f2f

@@note to self: during charter review, note that the format of publications is part of W3C process. @@also be sure to talk about related groups: TAG, RDF Core, XML Query, ... @@also: introduce the group to Web Architecture: URIs etc.


in progress; to follow within 2 weeks of the meeting.

based on IRC log: Mon, 14 Jan, Tue, 15Jan

Welcome - Logistics overview, etc. (14:17Z)

The host welcomed the participants. The 27 participants representing @@ W3C member organizations introduced themselves:

see also:wg membership

  1. James Barnette, Defense Information Systems Agency (DISA)
  2. Brickley @@
  3. Jeremy Carroll, Hewlett Packard Company jjc@hplb.hpl.hp.com, jeremy_carroll@hp.com (intro)
  4. Dan Connolly, W3C Team contact connolly@w3.org
  5. Jonathan Dale, Fujitsu Limited jdale@fla.fujitsu.com (intro)
  6. Jos De Roo, Agfa-Gevaert N. V. jos.deroo.jd@belgium.agfa.com (intro)
  7. Mike Dean mdean@bbn.com (invited expert; intro)
  8. Stefan Decker, Stanford stefan@db.stanford.edu (intro)
  9. Dieter Fensel, Ibrow, dieter@cs.vu.nl (intro)
  10. Tim Finin, University of Maryland MIND Laboratory finin@cs.umbc.edu (intro)
  11. Nicholas Gibbins, University of Southampton nmg@ecs.soton.ac.uk (intro)
  12. Jeff Heflin heflin@cse.lehigh.edu (invited expert; intro)
  13. James Hendler, Maryland Information and Network Dynamics Lab at the University of Maryland hendler@cs.umd.edu (chair; intro)
  14. Ziv Hellman, <ziv@unicorn.com>, Unicorn Solutions Inc. (intro)
  15. Ian Horrocks, Network Inference horrocks@cs.man.ac.uk (intro)
  16. Deborah McGuinness, Stanford dlm@ksl.stanford.edu (intro)
  17. Libby Miller, University of Bristol libby.miller@bristol.ac.uk (intro)
  18. Leo Obrst, MITRE lobrst@mitre.org (intro)
  19. Laurent Olivry EDF (Electricite De France) Laurent.Olivry@edf.fr
  20. Peter Patel-Schneider, Lucent Technologies pfps@research.bell-labs.com (intro)
  21. Marwan Sabbouh, MITRE ms@mitre.org (intro)
  22. Guus Schreiber, Ibrow schreiber@swi.psy.uva.nl (intro)
  23. Shimizu Noboru, Interoperability Technology Association for Information Processing, Japan (INTAP)
  24. Michael Smith, Electronic Data System (EDS) michael.smith@eds.com (intro)
  25. Lynn Andrea Stein, lynn.stein@olin.edu (invited expert; intro) (1st day only)
  26. Frank van Harmelen, Ibrow Frank.van.Harmelen@cs.vu.nl (intro)
  27. Raphael Volz, <volz@fzi.de>, Forschungszentrum Informatik (FZI) (intro)

regrets: Trastour (08 Jan 2002 10:30:41 +0000)

Charter Review (14:25Z)

Hendler reviewed the charter as well as the history of the formation of the group, including the director's decision, and the context: other related groups, etc.

Connolly breifly reviewed W3C process, noting that in the end, it's a tool toward the goal of getting new technologies deployed.

The group confirmed its earlier (3 Jan 2002) decision to name its language OWL. Hendler noted some history of the name, which we agreed to acknowledge.

DAML+OIL Technical Detail (15:38Z)

Ian Horrocks presented DAML+OIL Techinical Detail (cf msg of 14 Jan) @@PDF -- sufficiently accessible? and briefly demonstrated oiled, which does reasoning from DAML+OIL knowledge bases.

@@notes from Frank vH???

Use Case Discussion I (18:02Z)

Hendler suggested that our goal is a W3C working draft with roughly the following outline:

  1. compelling use cases (5ish)
  2. requirements arising from use cases
  3. appendix containing additional use cases not contributing to 2

later it was suggested, and generally agreed, that high-level design goals should be included as well. @@when was that?

Connolly suggested that we use "requirement" in the sense of "if we don't have this, we're not done"; things that we generally agree are desireable but not essential should be called "goals".

Guus Schreiber presented Use cases: collection management.

ACTION Stein: explain "many systems, including frame and oo systems in which metaclasses are used in this way" (18:20Z)

ACTION guus: to provide slides

We took a straw poll around several of the requirements:

POLL: classes as instances of other classes
strong agree
POLL: definitional constraints
mostly unclear; none in favor.
POLL: default knowledge
mostly against, some in favour
POLL: part/whole relations
mostly opposed, few in favour
POLL: property typing
mostly in favour, couple against, few don't care
Leo Obrst presented requirements related to Content Interoperability (18:56Z). We took straw polls around selected requirements:
POLL: inter-ontology references 3.1.1
mostly in favour
POLL: ontology mapping rules, features 3.1.3
jimh rules poll out of charter. see later discussion of why
POLL: ontology composition language 3.1.4
mostly in favour
POLL: inter-ontology sysnonyms/aliases 3.1.8
mostly in favour, no against, few don't care/know
POLL: ontology approximation 3.1.11
mostly against, few don't care, couple in favour
POLL: inter-ontology validation 3.1.12 (annotation/tagging wrt consistency)
most in favour, some disagree, significant number of don't know/care

Stefan Decker presented requirements arising from Web Services use cases (19:26Z).

POLL: language must have a small footprint
mostly against
POLL: language defn is organised in layers
mostly in favour, some against, few neutral
POLL: precisely described semantics
jimh overrules: required by charter
POLL: datatypes in language
mostly in favour
POLL: ability to express relations between types (eg. inequalities on numbers)
jimh postpones

ACTION on Stefan's group to discuss further tomorrow

POLL: ability to give ontologies names and the ability to denote membership of a class in an ontology
mostly in favour, few opposed, few don't know

ACTION pfps: determine status of IP on this issue

Jeff Heflin presented OWL General Requirements. (20:15Z)

ACTION jeffh: to bring implications of this use of subClassOf to attn of RDF Core WG (in context)

POLL: versioning should be requirement for language
mostly in favour, few opposed, few don't care
POLL: subclass/superclass, inverse, equivalence
all in favour
POLL: complex extensions
mostly against, one in favour, few don't know

SWOL Discussion (21:17Z)

Peter Patel-Schneider presented:

This led to techincal discussion of desirable properties of formal systems etc. No actions/decisions.

Adjourn 'till tuesday...

DAML+OIL Use Review (14:20Z)

Mike Dean presented DAML+OIL Issues and Experiences.

Mention of frame-based system sparked a discussion of user communities. Hendler observed that there are at least two different user communities, and we should be aware of the needs (including documentation, ...) of the various communities.

Hendler clarified our charter w.r.t. rules: it's recognized that rules are needed in the Semantic Web, but ontologies are speparable, and there's more consensus on the technical design at the ontology level


A break-out session followed, with groups forming around each of the use-case areas.

Compiling Requirements (18:17Z)

Hendler compiled requirements from the 4 groups.

ACTION JimH: send table of requirements. Done: requirements poll results.

See also:

ACTION Hefflin, Jonathan D., Rafael V.: to draft a requirements document by end of jan.

ACTION danc Ian and mike Dean: will work on a document which evaluates how well daml+oil meets the owl requirements as identified at this f2f meeting

Hot Topics: Decidability, Computability, Efficiency (19:47Z)

@@I think Hendler summarized the discussion, but I don't see it in the logs. Help, Jim?

ACTION ian and frank are delegated the task to come up with the descriptive adj for the reasoner.

Hot Topics: Layering, RDF compatibility (20:19Z)

We reviewed some terms:

Three or four possibilities emerged:

  1. a syntactic embedding of owl into rdf:

    OWL : RDF :: RDF : XML

    Syntax: Every OWL document is syntactically an RDF document.

    Semantics: some RDF-entailment conclusions contradict OWL-entailment conclusions. OWL is not sound nor complete w.r.t. RDF(S).

  2. owl has syntactic features that go beyond rdf

    OWL : RDF :: FOPL : propositional calculus

    Syntax: some OWL documents aren't RDF documents.

    Semantics: OWL is complete w.r.t. RDF but (of course) not sound.

  3. OWL shares syntax and semantics with RDF

    This leads to paradoxes, as noted earlier.

a fourth possibility is peter's owl', in which owl' is a semantic restriction of a syntactic restriction of rdfs

DanC does a staw poll on the three suggestions: which is your favorite? which can you not live with?

  1. ~8 prefer; 1 opposed
  2. ~2 prefer; ~2 opposed
  3. 1 prefer; ~7 opposed

Frank vH observed that perhaps the most significant conclusion to be drawn from these data is that many participants have not arrived at any position on these issues.

ACTION PeterPS, Dieter, Mike Smith: write up layering issues (21:08Z)

14:30 - 15:00 break

Discussion/Planning (21:29Z)


Discussion of next steps for group Determination of calendar for next f2fs

(also: next meeting discussion of 14:09Z, 18:15Z)

ACTION JimH: send ftf schedule proposal