F2F1 Minutes

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See F2F1 and F2F1 Agenda.

Contents

Attendance

Present
Peter Haase, Boris Motik, Bernardo Cuenca Grau, Steve Battle, Jeremy Carroll, Peter Patel-Schneider, Uli Sattler, Michael Smith, Bijan Parsia, Giorgos Stoilos, Pascal Hitzler, Markus Krötzsch, Vit Novacek, Ivan Herman, Sandro Hawke, Deborah McGuinness, Evan Wallace, Rinke Hoekstra, Ian Horrocks, Ratnesh Sahay, Alan Ruttenberg
Remote
Achille Fukoue, Elisa Kendall, Jim Hendler, Joanne Luciano, Vipul Kashyap, Zhe Wu
Observers/Guests (Full-Time and Part-Time)
Alan Rector, Peihong Ke, Robert Stevens, Sean Bechhofer, Sebastian Brandt, Thomas Schneider, Dimitri Tsarkov, Matthew Horridge, Carsten Lutz
Regrets
Anne Cregan, Fabian Neuhaus, Fabien Gandon, Martin Dzbor, Tommie Meyer
Chair
Ian Horrocks, Alan Ruttenberg

Session 1 (Day 1, 9:00 - 10:45)

The text of this section is automatically included from F2F1 Minutes Session 1. Edits should be done there.


Welcome, Logistics, Introductions

Peter Haase

Boris Motik

Boris Motik: I'm boris motik, University of Oxford

Bernardo Cuenca Grau

Steve Battle

Jeremy Carroll

Peter Patel-Schneider

Uli Sattler

Carsten Lutz, Dresden (guest, joining)

Thomas Schneider (guest)

Michael Smith

Bijan Parsia

Sebastian Brandt (guest)

Matthew Horridge (guest)

Giorgos Stoilos

Pascal Hitzler

Markus Krötzsch

Vit Novacek

Ivan Herman

Sandro Hawke

Deborah McGuinness

Evan Wallace

Rinke Hoekstra

Sean Bechhofer (guest from Manchester)

Robert Stevens (guest from Manchester)

Ian Horrocks (University of Manchester [sic])

OWL 1.0 Implementation Experience

Speaker - Matthew Horridge - slides

Matthew Horridge: implementing OWL DL experience

Matthew Horridge: problems - RDF and imports

Matthew Horridge: internal API is known as the OWL API - based on OWL abstract syntax

Matthew Horridge: use of OWL API means that different concrete syntaxes can be used

Matthew Horridge: problems with abstract syntax - distinguishing between, e.g., data and object properties

RDF

Matthew Horridge: effort required - RDF parser is vast majority of effort, everything else is much easier

Matthew Horridge: similar situation for OWL 1.1 API

Ivan Herman: what is the "RDF parser"

Matthew Horridge: RDF parser is just triples to internal API, not dealing with RDF/XML

Matthew Horridge: RDF mapping - want to be fast, small, and streaming

Matthew Horridge: streaming was too hard, so the parser was not streaming

Matthew Horridge: in new parser - parser is streaming, but still takes resources

Matthew Horridge: OWL XML is very verbose - causes problems

Jeremy Carroll: what is the size increase

Matthew Horridge: not sure - 3 to 5 times

Matthew Horridge: triples to OWL API was problematic - inversing a non-deterministic mapping

Matthew Horridge: OWL 1.1 thus has two mappings

Matthew Horridge: e.g., subclass (see slides)

Matthew Horridge: other problem - n-ary constructs go to n or n*n triples

Matthew Horridge: failures of round tripping cause problems

Matthew Horridge: missing type triples make ontologies officially non-parsable

Matthew Horridge: in many cases there is a fix, but sometimes the fix is not local (may require looking at imported ontologies)

Jeremy Carroll: declaration is good style - RDF graphs are unordered - so declarations can be non-local

Michael Smith: searching for declarations require two passes - which can be expensive

Alan Ruttenberg: why not do typing "as seen"

Boris Motik: this requires deferring processing, and is hard

Bijan Parsia: in any case, there is a lot of extra work to make the RDF parsing go through

Jeremy Carroll: there are implementations that do good jobs

Bijan Parsia: no - there are bugs

Jeremy Carroll: but you do get benefits - use of RDF

Bijan Parsia: but there is a cost

Jeremy Carroll: multiple vocab is an attempt to fix this?

Bijan Parsia: yes

Alan Ruttenberg: compatibility means that there is no way out

Jeremy Carroll: Streaming OWL DL; ESWC 2004; JJ Carroll; LNCS 2004, ISSU 3053, pages 198-212
Jeremy Carroll: describes a streaming approach to OWL DL species validation
Jeremy Carroll: (but its hard)

Ian Horrocks: if we make a better way, then the old versions will die out (eventually)

Imports

Matthew Horridge: imports issues

Matthew Horridge: if //...foo.... imports //...bar... what does it mean?

Matthew Horridge: name of an ontology or a location of an ontology

Matthew Horridge: what if the name and the location don't match

Matthew Horridge: imports on OWL DL is controlled by OWL S&AS 3.4

Matthew Horridge: OWL reference says imports is by location

Matthew Horridge: OWL guide says something confusing

Matthew Horridge: want some direct and normative statement

Jeremy Carroll: section 5 OWL S&AS:
Jeremy Carroll: - Definition: Let T be the mapping from the abstract syntax to RDF graphs from Section 4.1. Let O be a collection of OWL DL ontologies and axioms and facts in abstract syntax form. O is said to be imports closed iff for any URI, u, in an imports directive in any ontology in O the RDF parsing of the document accessible on the Web at u results in T(K), where K is the ontology in O with name u.
Jeremy Carroll: (that definition is clear)

Matthew Horridge: solution was by name (essentially)

Matthew Horridge: what is the name of an ontology?

Matthew Horridge: guide is confusing

Matthew Horridge: test cases for OWL 1.0 were very useful - we need them for 1.1

Matthew Horridge: OWL 1.1 SS diagrams were useful

Jeremy Carroll: we need some time to talk about testing

Bijan Parsia: yes - infrastructure is needed

Jeremy Carroll: probably only need a short amount of time

Introductions (additions)

Alan Rector (guest from Manchester)

Ratnesh Sahay (DERI Galway)

Alan Ruttenberg

History (including OWLED)

Speaker - Bijan Parsia (no slides)

Bijan Parsia: OWLED - started in 2005 to let people interested in OWL design and use together

Bijan Parsia: there was about 1.5 years of experiece in OWL - there were complaints (particularly QCRs and datatypes)

OWL 1.1

Bijan Parsia: idea for a "bug fix" update to OWL - things that are relatively easy and wanted

Bijan Parsia: particularly wanted by users

Bijan Parsia: workshop was (largely) to discover what this new version would be

Bijan Parsia: workshop was adjacent to ISWC 2005 - about 60 participants

Michael Smith: mailing list archives for initial owled community http://lists.mindswap.org/pipermail/owl/
Michael Smith: workshop design summary first msg: http://lists.mindswap.org/pipermail/owl/2005-November/000001.html

Bijan Parsia: desiderata for changes:

Bijan Parsia: 1/ requested by major users

Bijan Parsia: 2/ have effective reasoning methods

Bijan Parsia: 3/ will be implemented

Bijan Parsia: (alternatively commitment from users, well understood, committment from implementers)

Bijan Parsia: other goals: quiet whining, promote apps, improve spec, move forward, path for extensions, reduce species confusion (particularly DL/Lite)

Bijan Parsia: example - move OWL-S to OWL DL

Bijan Parsia: tool feature - coercion to OWL DL in Pellet

Jeremy Carroll: tools *should* do this

Bijan Parsia: *mostly* get the right thing

Bijan Parsia: there are still things that people want to do - e.g., lists

Bijan Parsia: I implemented shadow lists -- RDF Lists with a parallel vocabulary, just a different namespace. Pellet can do this silently.

Jeremy Carroll: can rdf:list be fixed?

Bijan Parsia: issues of modelling lists (eg, breaking them) affecting syntax

Alan Ruttenberg: are lists necessary?

Bijan Parsia: yes

Peter Patel-Schneider: Lists are only in RDF because OWL-WG demanded them.

Peter Patel-Schneider: We needed them for the OWL syntax

Deborah McGuinness: consensus on what do to?

Bijan Parsia: no, just consensus on desiderata

Bijan Parsia: OWL 1.1 design is driven by the three main desiderata

Carsten Lutz: are all three needed?

Bijan Parsia: not in all cases, but in most cases

Stability vs Missing Features

Jeremy Carroll: some groups want stability

Bijan Parsia: main desiderata do lean towards stability

Ivan Herman: there is still a long process to use OWL, so change is bad

Jeremy Carroll: HP didn't participate in OWLED due to financial desires

Alan Rector: missing features in OWL have hindered uptake

Bijan Parsia: currently missing feature is keys

Ivan Herman: different markets - some want more features, some want no change

Peter Patel-Schneider: why?

Bijan Parsia: why should people who are only taking taking part of OWL care about OWL being extended?

Sandro Hawke: This is "OWL Pixie Dust". People want some of the OWL Magic, without really knowing what OWL is or does for them......

Alan Rector: standards all change so why is new OWL a problem?

Joanne Luciano: they might care if backwards compatability would break

Alan Rector: there are issues with backward compatibility

Alan Rector: Standards grow, with backward compatibility. And sometimes there are mistakes that need to be fixed.

Ian Horrocks: maintenance is needed

Deborah McGuinness: users want transition path and backwards compatibility

Joanne Luciano: and fixing mistakes or updating costs.
Joanne Luciano: updating has costs associated with it is what I meant to say

Ivan Herman: we need to take care of stability concerns

Bijan Parsia: model of development - do lots of work outside W3C, then quick recommendation, repeat roughly yearly

Ivan Herman: stability - vague uneasiness (mostly)

Alan Ruttenberg: what can we do to help?

Ivan Herman: nothing, really

Sandro Hawke: if the perception is that OWL 1.0 is broken then that is even worse than the perception that things are unstable because we're working on 1.1

Jeremy Carroll: Bijan quoted DannyAyers "Don't hurt the triples"

Alan Rector: for me OWL 1.0 is not usable - so I need OWL 1.1

Bijan Parsia: look for people who have real blockage and try to help them

Effect of OWLED

Bijan Parsia: Bijan: OWLED attendance and submissions have been growing

Bijan Parsia: many participants felt that OWLED gave them a voice

Bijan Parsia: OWLED experience has been positive

Bijan Parsia: testimonial from Kent Spackman (SNOMED person)

Sandro Hawke: adjourn for coffee


Session 2 (Day 1, 11:15 - 13:00)

The text of this section is automatically included from F2F1 Minutes Session 2. Edits should be done there.


Structural Specification and Functional-Style Syntax design review

(see issues Issue 4, Issue 16, Issue 65 and Issue 82

Slides for this session: Media:motik-f2f1.pdf

(Scribe changed to Jeremy Carroll)

Uli Sattler: Peihong Ke has joined as a guest/observer

Boris presents slides - OWL 1.1 Design Decisions

General Design Principles (slide 3)

  1. extend expressivity
  2. Bring spec closer to tools. Some features of OWL 1.0 have not been implemented correctly.
  3. make spec cleaner and clearer

Structural Specification: slides 4 and 5

Every OWL API wants to provide "what are the classes in this ontology", but what does that mean for OWL?

Discussion of mention; use; definition? It is very difficult to decide between these.

Jeremy Carroll: why does this matter?

Boris Motik: The tool builders need answers. EG protege gives a list of classes. [Scribe assist by Sandro Hawke]
Peter Patel-Schneider: If protege and swoop list different classes, who cares...??? [Scribe assist by Sandro Hawke]

Bijan Parsia: if we can improve interop on this, we should ...

Bijan Parsia: let's only have UI variance if it's useful. [Scribe assist by Sandro Hawke]

Alan Ruttenberg: if these are design criteria they should be exposed

Boris Motik: there are some explicit answers in the new spec

Boris Motik: W3C should care, because these things are implicit

Peter Patel-Schneider: I still haven't heard a useful answer for tool designers

Alan Ruttenberg: two people are looking at some ontology in two different lists - "please look at class FooBar ..."

Joanne Luciano: to alan. what do you mean "in two different lists?"

Peter Patel-Schneider: but there's lots of example where two different UIs are difficult to interop

Jeremy Carroll: let's have tests

Joanne Luciano: to Jeremy..tests would be good, but what kind of tests do you mean?

Bijan Parsia: serialization tests would be good -


Bijan Parsia: users care abotu serialization

Bijan Parsia: OWL API


Ratnesh Sahay: a java program on two different dev environments, my program should behave similarly

Ratnesh Sahay: we care more about behaviour of program, than behaviour of tool

Ian Horrocks: the set of classes in an ontology should be well-defined

Michael Smith: for explanation and debugging it is useful to have a mapping from entity or axiom to ontology

Jeremy Carroll: isn't OWL 1.0 clear?

Jeremy Carroll: requires xx rdf:type owl:Class

Boris Motik: e.g. imports or inferred triples

Alan Ruttenberg: what is the underlying design model?

Alan Ruttenberg: If the question is "What classes are mentioned in this ontology?" then we're fine. It's not clear to me that any other question is relevant/important. What motivates other questions?

Boris Motik: we want to design OWL 1.1 as an object model

Matthew Horridge: imports was too vague

Sebastian Brandt: many industrial users like object models; descriptions of triples are much less accessible


someone (maybe Alan): Object oriented modeling of OWL, cuts both ways: A lot of teaching OWL is unteaching object oriented thinking.

slide 6

expressivity enhancements uncontroversial

Metamodelling (slide 7)

metamodelling needed also in OWL DL

e.g. an OWL-S type example

punning is a possible solution,

applications want syntactic level, and don't want consequences

Peter Patel-Schneider: which reasoners could support Hilog semantics, after minor changes

bijan/boris (guest): easy to modify pellet

B. Motik. On the Properties of Metamodeling in OWL

Bijan Parsia: easy cases would be easy ...

slide 8

B-nodes

slide 9

Jeremy Carroll: huge exlamation on first bullet

Bijan Parsia: OWL Semantics 1.0 is clear, OWL DL name, OWL Full location

Alan Ruttenberg: caching is a tool's issue

Alan Ruttenberg: caching does not break the spec

Bijan Parsia: some implementations change name when ontologies move

Alan Ruttenberg: if I moved ontology from http:... to file:... then I can't import it, and then spec is broken

Michael Smith: session on imports at 1400?

Alan Ruttenberg: disagrees with first bullet

we agree that we don't agree, but we're not clear what we don't agree on

Joanne Luciano: alan, is the spec broken or the ontology broken?

slide 10

Alan Ruttenberg: I agree with everyone who disagrees with themselves
Joanne Luciano: Then we are in agreement.

Bijan Parsia: we have session on annotations

Sebastian (guest): annotations on axioms are useful

slide 11

slide 12

Peter Patel-Schneider: all OWL DL reasoners are based on nonnormative docs

(sorry scribe missed a bit)

Bijan Parsia: it would be better if the implementors were working more closely from normative docs

Ian Horrocks: there is no claim that sean's nonnormative doc and normative spec say same thing

discussion on pellet and bnodes --

Alan Ruttenberg: pellet departs from spec

Bijan Parsia: we (pellet team) made choices

Alan Ruttenberg: No reasoner completely implements spec. Didn't mean to pick on Pellet - it's just the one I know best [Scribe assist by Alan Ruttenberg]

slide 13

Alan Ruttenberg: Pellet is most complete, in my experience


slide 15

(Scribe changed to Pascal Hitzler)

Alan Ruttenberg: interaction of typing with RDF really a problem?

Alan Ruttenberg: is the problem in the language or in the documentation of it?

Bijan Parsia: pellet does some repairs silently. spec could go in a similar direction

Jeremy Carroll: questions on slide 15 answered on OWL 1.0 spec

Boris Motik: some may be, but spec might need fixing or made more explicit

Ian Horrocks: more clear spec desirable

Bijan Parsia: agrees about unclear parts in the spec

Alan Ruttenberg: Alan agrees too. Took me a year, I reckon, to understand OWL

review of and resolution to publish Syntax, Semantics, and Mapping-to-RDF documents as First Public Working Drafts

next session: discussion and decisions on publication schedule and first public working draft

chaired by Ian Horrocks


collecting issues: (1) shortname, (2) document titles, (3) SOTD, (4) WIKI extraction, (5) attribution etc.


Ivan Herman: (1) should include namespace

Ian Horrocks: need to decide if namespace is an issue

Bijan Parsia: need to do editorial cleanup (part of (4))

Bijan Parsia: deadlines need to be watched

(1) short name (+ namespace)

suggestions: owlwot, alan: owltoo

Alan Ruttenberg: calling it OWL may overload and thus be difficult

... something neutral to version name?

Sandro Hawke: no problem with same names

Alan Ruttenberg: might be confusing

Ian Horrocks: http://www.w3.org/TR/owl-guide/
Ian Horrocks: http://www.w3.org/TR/owl-ref/
Ivan Herman: current names: owl-features, owl-guide, owl-ref, owl-semantics, owl-test, webont-req
Ian Horrocks: http://www.w3.org/TR/owl-semantics/
Ian Horrocks: http://www.w3.org/TR/owl-test/

Sandro Hawke: using same name is only a problem if exactly the same document name is used

Ian Horrocks: http://www.w3.org/TR/webont-req/
Ian Horrocks: http://www.w3.org/TR/owl-xmlsyntax/

Evan Wallace: so why not call it OWL1.1?

Bijan Parsia: OWL1.1 is one possibility

Sandro Hawke: you want a URL which is the link to the latest version of the spec

Evan Wallace: you need a name which redirects to the short name?

Peter Patel-Schneider: eventually pointers to owl1.1 docs might go away ...

... but that's independent of the document names

Sandro Hawke: I see .... in going from 1.1 to 1.2 we're going to have the same problem, so yes, the short-name needs the version. because the WD shadows the REC.
Joanne Luciano: call it OWL-DL?  :-)

Ian Horrocks: we can't use "owl-semantics" right now.

Ivan Herman: because that's the working draft

Bijan Parsia: OWLWOT, OWLTOO looks strange

... proposes OWL1.1 or OWL11 or OWL-11

Ian Horrocks: what about OWLTOO

Sandro Hawke: different names suggest different levels of compatibility

Deborah McGuinness: yes - current proposals are owl1.1 and owl1-1

Bijan Parsia: OWL1.1 (with any kind of minor changes)

Joanne Luciano: I like OWL 1.1 - don't fix what aint broke :-) (thanks!)

sugestions OWL 1-1, OWL11, OWL-1-1

Ivan Herman: decision has to be formally recorded according to charter

Ian Horrocks: should discuss point (2) at the same time

... what is going to be named in document title?

Alan Ruttenberg: procedural question: can we resolve this here? what about absent people?

Bijan Parsia: explains: may not resolve things which have not been on the agenda

Peter Patel-Schneider: may be arguable

Ivan Herman: was the issue of document titles on the agenda?

some discussion about which things that can be resolved in the F2F

Alan Ruttenberg: supports bijan that we should decide things, and people can appeal to chairs to reopen the issue

Sandro Hawke: in this case: does it need to be decided right now?

Deborah McGuinness: against owl2/owltoo

ian makes straw poll 1.1 against 2 (clear positive outcome for 1.1)

Ian Horrocks: let's decide for 1.1

proposed and resolved: it's going to be 1.1 (in some form)

PROPOSED: Our publications will refer to this work as "OWL 1.1" (not OWL 2.0, etc)

Ian Horrocks: asks for objections, abstantions on that. none recorded

Alan Ruttenberg: any objections?

RESOLVED: Our publications will refer to this work as "OWL 1.1" (not OWL 2.0, etc)

Sandro Hawke: (no abstentions, no objections)

Ivan Herman: other specs seem to use similars to OWL11

Sandro Hawke: would like to postpone this and find out some background

Ian Horrocks: straw poll: do we want "owl11" ?

PROPOSED: To ask for shortname "owl11-[whatever]"

Sandro Hawke: some interest in OWL-1-1
namespace

Ian Horrocks: what about namespace?

Ivan Herman: tough one

Peter Patel-Schneider: proposes brief discussion about it

Peter Patel-Schneider: should reuse the namespace

several people second reusing the namespace

Alan Ruttenberg: I know now that I don't know whrether to resuse ns

straw poll on this: tendency for reusing namespace, but not uncontroversial

Alan Ruttenberg: if owl constructs change semantics then it may be difficult to reuse name space

Ulrike Sattler: wasn't the idea not to change any of the constructs already present?

Ivan Herman: are we sure this won't happen?

Ian Horrocks: we don't have to decide on this right now

Bijan Parsia: new constructs should have new names

... we will add new things into to the namespace

... expanding vocabulary is considered difficult by some people

Ian Horrocks: summary: tendency for reusing, but issue can be postponed

Peter Patel-Schneider: need to be careful on first working draft that it doesn't cause confusion in terms of namespace

Alan Ruttenberg: Just to put it on the record, I also lean to reusing the namespace. Just worried about the unknown unknowns

bijan takes action to take care of this

ACTION: Bijan to put alert box in all the documents about the status of the namespace


Alan Ruttenberg: say it "owl" subject to change, not "owl11" subject to change.

Boris Motik: old names are still in old namespace (current document)

Joanne Luciano: We need to be careful not to make "OWL" "OUCH"

Bijan Parsia: suggests to leave the two namespaces as they are right now

Bijan Parsia: let's not make owl 1.1 implementors change anything right now.

Joanne Luciano: I agree with Bijan ... not make owl 1.1 implementors change anything right now

Bijan Parsia: there are owl 1.1 ontologies on the web right now.

Alan Ruttenberg: straw poll: leave as is with warnings (agreed)

boris has action to do the changes (add warnings) in the docs

Joanne Luciano: warnings are good

ivan about doc titles: suggests owl11 DL

Ivan Herman: functional syntax doc is DL-only, so that should be in the title?

Ian Horrocks: functional syntax is not entirely irrelevant outside DL

Alan Ruttenberg: needs to be decided later

Ian Horrocks: see 1.0 docs on abstract syntax

Bijan Parsia: in some way structural syntax specifies OWL Full

Ivan Herman: but there are statements which cannot be expressed in it

... should not forget that this is an issue

Ian Horrocks: action on this?

Ivan Herman: need a list of editors first?

moving on to point (5): attribution etc.

Alan Ruttenberg: proposes for current draft that attributions should be as they are

... next draft if substantive changes, attributions should be reevaluated

Bijan Parsia: question is if chairs want to assign editors. bijan suggests chairs do that

Alan Ruttenberg: would like to not do that right now

Peter Patel-Schneider: somebody needs to put more work into it soon ... credit should be given

Ivan Herman: seconds alan: currently mentioned people stay editors for the current version

some more discussion on editors for current version

Bijan Parsia: wants editors assigned now

alan proposes current authors are editors for the current version

Joanne Luciano: I believe I have funding now that could support my ability to contribute as an editor

Ian Horrocks: should now decide whose job it will be

Ian Horrocks: proposal that boris, peter and bijan work on syntax (they would agree)

Ian Horrocks: bernardo, boris for semantics document? would agree as well

... bernardo, boris would also do the mapping document

... are we happy if they do it?

... straw poll on this: no objections

was agreed that attributions will stay the same in current version of the documents as they are stated right now

Joanne Luciano: so is there no room for me to contribute and be attributed?

Ivan Herman: doesn't it need to be called editor?

Sandro Hawke: I doubt it

Ian Horrocks: If it has to change from author to editor, then that can be chairs decision

cgi-irc (guest): Joanne, we're only talking about FPWD
cgi-irc (guest): We've not mentioned acknowledgements (for examle)
cgi-irc (guest): And this is explicitly temporary
Joanne Luciano: what's FPWD?
Sandro Hawke: First Public Working Draft

moving to point (4): editorial cleanup in the wiki plus wiki extraction

issues from working drafts will stay

Alan Ruttenberg: useful comments should be left but scripted away

moving to point (2): resolution to publish Syntax, Semantics, and Mapping-to-RDF documents as First Public Working Drafts

PROPOSED: Publish Syntax, Semantics, and Mapping-to-RDF documents as First Public Working Drafts

Ian Horrocks: straw poll - no objections

PROPOSED: Publish Syntax, Semantics, and Mapping-to-RDF documents (as on the wiki right now) as First Public Working Drafts

Sandro Hawke: using http://www.w3.org/2000/09/dbwg/details?group=41712&public=1&order=org

Ian Horrocks: formal vote on this (reminder: only one vote per member): W3C abstains, no objections

Sandro Hawke: In favor: all member orgs present in room.
Alan Ruttenberg: joanne?
Alan Ruttenberg: if you are there, could you please vote on proposal?
Joanne Luciano: i'm here
Joanne Luciano: in favor
Ian Horrocks: Anyone else out there who would like to vote?

RESOLVED: Publish Syntax, Semantics, and Mapping-to-RDF documents (as on the wiki right now) as First Public Working Drafts

moving to (3): SOTD

brief agreement that this shall not be discussed now

Ian Horrocks: lunch break now

Sandro Hawke: Lunch.

Bijan Parsia: thanks to sean for taking care of organisation ...

Sandro Hawke: scribe after lunch to be markus


Session 3 (Day 1, 14:00 - 15:45)

The text of this section is automatically included from F2F1 Minutes Session 3. Edits should be done there.


(Scribe changed to Markus Krötzsch)

Imports

Slides for this session: Media:pfps-f2f1.pdf (go to page 5)

Wikipage: http://www.w3.org/2007/OWL/wiki/Imports

Peter Patel-Schneider repeats imports definitions from OWL DL, OWL Full

(compare http://lists.w3.org/Archives/Public/public-owl-wg/2007Nov/0565.html)

Ian Horrocks: Peter's talk just sent by email and is also at http://www.cs.man.ac.uk/~horrocks/peter-talk.html
Bijan Parsia: Text on screen is also on: http://www.w3.org/2007/OWL/wiki/Imports

Peter Patel-Schneider: differences relate to whether ontology names or locations are assumed in import statements

Bijan Parsia: not all ontologies have names, right?

Peter Patel-Schneider: yes, only importable ontologies need a name.

Peter Patel-Schneider: this appears to be a bug

Boris Motik: (1) there should be only one kind of import, not three

... (2) it should be possible to reconstruct the location from whic some statement was imported from, e.g. for editing

Bijan Parsia: the name and location can be different, the question is how to deal with it. This seems to be agreed on.

Peter Patel-Schneider: OWL1.1 imports are based on ontology names only

... this is completely different from OWL1.0, where the name must be the location.

... We do not have XML inclusions (a mechanism working with location only).

Joanne Luciano: what are the implications of the differences?

... Summing up there are two different designs: name and location based importing.

Peter Patel-Schneider: various questions arise

... (1) should every ontology (be forced to) have a name?

... (2) should name and location be the same (i.e. should the name always indicate the location)?

... (3) should imports be by name or by location?

Jeremy Carroll: this seems to be a general web architechture issue.

Bijan Parsia: in general URIs are not locations, but there might be (multiple) hints for actually finding the document.

Alan Ruttenberg: are imports broken? [Scribe assist by Jeremy Carroll]
Peter Patel-Schneider: no [Scribe assist by Jeremy Carroll]
Boris Motik: yes [Scribe assist by Jeremy Carroll]
Jeremy Carroll: no [Scribe assist by Jeremy Carroll]

Peter Patel-Schneider: versioning is another problem

Alan Ruttenberg: this goes beyond the importing issue

Peter Patel-Schneider: every importable ontology needs some location, but it need not be on the web

Boris Motik: a typical use case is that two ontologies (one importing the other) reside in some file repository and then are moved to the web. How do you support this?

... locations change over time

... this is not just a caching issue

... What they are doing in XML Schema may be a good solution.

... When importing an ontology, I do not care where it lives. It might even have many copies.

Achille Fokoue: +1 for an approach similar to XML Schema

Alan Ruttenberg: I suggest that names and locations might be different, but importing one ontologies from some location should also make this location a name for the ontology.

Bijan Parsia: I do not understand the proposal

Alan Ruttenberg: every importable ontology has a name which is also a location, but it is possible that the same ontologies have different names in the sameAs-sense.

... importing may lead to the inference (?) that two names refer to the same ontology.

General agreement that further clarification is needed.

Alan Ruttenberg: every name should be a location, they are linked together.

... just if a name does not match its location, then this alternative name should be deduced.

Bernardo Cuenca Grau: when you have an ontology name occuring in documents in different locations, how do you know they are the same?

Boris Motik: well, it is just *the*, say, Wine ontology

Bernardo Cuenca Grau: but there could be versions

... e.g. if someone adds axioms

Boris Motik: It's like Java classpath --- it's DELIBERATELY left out of the spec, so name-to-location can be handled in different ways. [Scribe assist by Sandro Hawke]

Boris Motik: this is not specified, but a similar mechanism is found in including classes in Java. Java uses names but the application environment must resolve the locations.

Joanne Luciano: it would be useful for me to see a table of options and tradeoffs

Jeremy Carroll: there are two cases: creating an ontology and publishing it, and the reverse, downloading and caching an ontology from the web.

... we should concentrate on the web/caching aspect, not on the publishing aspect.

Evan Wallace: Many people in ISO want to use URNs as a name, and these are not locations.

Alan Ruttenberg: I would also say that an ontology name is a URI, not always a URL, but to import it, you need a location which would then become a synonym.

Michael Smith: I second evan's observation that users choose ontology names that are intentionally not resolvable. e.g., tag URIs
Bijan Parsia: +1 to that seconding; "on the web, names == locations" is just false.
Joanne Luciano: +1 agree, separate and deal with separtely - nice proposal on the phone now

Achille Fokoue: the inclusion mechanism of XML Schema (XML Schema import not XMLinclude) is a good solution.

Joanne Luciano: who was just speaking?
Joanne Luciano: about the configuration file?

... names should not be tied to locations, but further sources should be used to resolve names.

Jeremy Carroll: achille was speaking

Alan Ruttenberg: is this consistent with my proposal for having many locations for some ontology?

Joanne Luciano: Thanks. His proposal makes sense to me

Achille Fokoue: yes, I would like some default mechanism that can be overwritten to specify alternative locations

Boris Motik: I have two points.

... (1) how many ontologies are really on the Web?

... (2) we should not specify in detail what tools are supposed to do when looking for ontologies

Achille Fokoue: and the overwrite should be done outside the owl file

... It would have been easier to leave tools some freedom for determining ontology locations, e.g. similar to CLASSPATH in Java

Ian Horrocks: Re (1) appliations may still refer to the web, but ontologies might stilll be local to some server

Joanne Luciano: even if it's not "on the web" now, we need to support the case that the ontologies are on the web

Boris Motik: but aren't there also relevant uses of ontologies without any Web?

Bijan Parsia: it is not out of scope to consider ontologies that are not on the web

... I am disagreeing with Alan.


... I often created local copies of ontologies to modify them, while keeping internal names.

... It shoud not happen that those modified copies then are deduced to be the same as the original one.

... I do not see what Alan's proposal buys us.

Ian Horrocks: summing up, the problem could be that multiple (versions of) ontologies have the same name in their header, and those should not be considered the same.

Alan Ruttenberg: this would only happen if both were imported.

... Considers, e.g. having three variants of one ontology:

... B, B', B''

... depending on what you import you may get either

... only if you import two at one time, these would be merged.

Bijan Parsia: but didn't you say that locations and names then get equated (sameAs) on import. Why would this be good?

Ian Horrocks: these details should be discussed here, and the discussion must probably be taken offline at some point.

... including clearly written-up proposals.

Bijan Parsia: Isn't this sent to the mailing list?

Alan Ruttenberg: responding to Jeremy saying that we should leave this to the caching mechanism. The reason that I would like to have "location punning" on names is that I would like to use different tools at one time.

Alan Rector (guest): Issues a) Scenarios please; b) if locations, need relative paths; c) relation between ontology name and base URI ("namespace") [Scribe assist by Alan Rector]

Sebastian Brandt (guest): I would like to partially agree with Boris: ontologies are often used offline to make money, but they still are developed online.

Boris Motik: Here is the part of the XML Schema specification about imports:
Boris Motik: http://www.w3.org/TR/xmlschema11-1/#composition-schemaImport

Matthew Horridge (guest): when developing tools, we only found it reasonalbe to treat ontology URIs as names. Protege uses a lookup table to map onologies to local files.

Sandro Hawke: Bottom line: is owl:imports like C #include (extended from filenames to URLs), or like java import (which needs classpath).

ACTION: Bijan to extend the wiki with information on imports and restructuring it if needed (with Sebastian)


ACTION: Alan Ruttenberg to write up his proposal on dealing with imports


Rich Annotations

Slides for this session: Media:pfps-f2f1.pdf (pp. 5-7)

Peter Patel-Schneider: basic ideas of rich annotations

Joanne Luciano: couldn't understand what AlanR said in response to the potentially infiinte nesting of annotations

... allow arbitrary syntax as annotations, including annotations

... annotations separated into "spaces" and some spaces may indicate that tools must understand the respective annotations (for extensions)

(Peter Patel-Schneider presents syntax slide)

Peter Patel-Schneider: keywords mayIgnore and mustUnderstand describe whether or not annotations are essential for semantics

Joanne Luciano: I don't understand what "space" means

... yes, annotations with "mustUnderstand" may change the semantics, also of existing constructs

... Each annotation belongs to some "space", given as part of the annotation syntax.

Joanne Luciano: is it a structuring of "the annotation space"

... There is a "default space" for annotations without explicit space annotations.

Bijan Parsia: the term "annotation" is ambiguous. In OWL1.0 it was something given to an annotationProperty. In OWL1.1 it can be any piece of syntax.

Peter Patel-Schneider: Annotations may even exist without relating to any OWL object.

Alan Ruttenberg: do the axioms of the containing ontology also belong to each annotation space?

Bijan Parsia: no, unless one would import it explicitly.

Boris Motik: I do not understand the idea of "annotation spaces"

Peter Patel-Schneider: this is because some annotations are semantic extensions, that should be keeped separate from other annotations.

Sebastian Brandt (guest): I have another use-case: I have some annotations that are just user documentations, some that contain "code" that is used by the application, and even some that are generated automatically by my applications.

Jeremy Carroll: we should have a worked example that illustrates this

Bijan Parsia: the Pronto extension to OWL provides some example

ACTION: Bijan to improve examples for rich annotations.


Boris Motik: it would also be useful if someone could explain in detail how to use this mechanism, starting from ontology creation up to external reuse.

Bijan Parsia: I can do that after coffee

Joanne Luciano: Bijan, count me in to your coffee break explaination

Alan Ruttenberg: is there going to be an RDF serialisation to this?

Bijan Parsia: yes

Alan Ruttenberg: do annotations then distribute over differnt files?

Bijan Parsia: no, we can use reification to add extra annotation-space information

... but there are many possibilities

Peter Patel-Schneider: I think the idea of annotation spaces changing the semantics of OWL is what is most controversial

Bijan Parsia: semantic annotation spaces need to have a spec, e.g. to include RIF rules into OWL documents.

... this spec then defines the intended semantics.

... The annotation space has a URI that may specify this semantics.

Peter Patel-Schneider: annotations usually have no semantics, exceptions being the mustUnderstand annotations that must be taken into account by tools in an adequate way.

Ian Horrocks: we did only talk about rich annotations, but not about the other OWL1.1 extensions to the OWL1.0 mechanism.

... this should also be discussed.

Peter Patel-Schneider: we can do that in the compatibility session tomorrow.

Coffee break.

Session 4 (Day 1, 16:15 - 18:00)

The text of this section is automatically included from F2F1 Minutes Session 4. Edits should be done there.


Rich Annotations

(Scribe changed to Deborah McGuinness)

The Working group would like to extend their thanks to the Knowledge Web project for the dinner we are about to enjoy.

Bijan's presentation of an annotation example

Slides sent to the list later

A few notes follow: The example uses one annotation space. One annotation blob includes who is responsible for the annotation (in this case self)

and sally checked it (thus showing structured annotations with reference to self)

namespaces at top

ontology header next

ontology uri, followed by comment (which expands to an rdfs comment)

Ian Horrocks: Two files:
Ian Horrocks: http://www.cs.man.ac.uk/~horrocks/prontoExample.owlfs
Ian Horrocks: http://www.cs.man.ac.uk/~horrocks/ontoClean.owlfs

followed by 2 namespace declarations

going down to womanaged50Plus

womanAged50Plus is a subclass of WomanWithBRCInShortTErm with certainty between .027 and .041

would be ignored if reasoner did not understand pronto

Joanne Luciano: can someone repeat how to read the certainty "0.027;0.041"?

certainty between .027 and .041

Question from Joanne - can this be used to embed sbml in the document? Alan Ruttenberg: annotation and must understand would allow you to embed sbml into the document

Boris Motik: how should one encode constraints into an ontology?

this could be a way

bijan notes ontoclean and pronto are working

Alan Rector: we need rich linguistic representations for some applications

Alan Rector: we need rich structure

Alan Rector: a lot of information is provenance knowledge, its structure and how it was put together which is important for passing around between tools

Alan Rector: this is also a way of providing one type of representation and projecting it into an alternative representation

Alan Rector: want to take a model in owl and export it in another syntax

Bijan Parsia: part of this "must understand" is a retrofit

Sandro Hawke: must understand may be a reasonable option but there may be other options as well

what if someone wanted to put in rif rules?

Sandro Hawke: If every axiom had a URI, you could just use RDF (or OWL, or RIF) [Scribe assist by Sandro Hawke]

one way you could interact with this is to make applications aware of the spaces

Bijan Parsia: yes [Scribe assist by Sandro Hawke]

Ian Horrocks: question to sandro - what are possibly better engineering solutions?

Sandro Hawke: ummm

Sandro Hawke: extend the syntax

Alan Ruttenberg: this may lead to many different extensions ... maybe this is "too easy"

Jeremy Carroll: generally amused by mustunderstand that may be ignored

Jeremy Carroll: concerning named graphs... what about serialization

into rdfxml

Bijan Parsia: you could reify, use literals, use separate documnets, etc ---- lots of ways to put named graphs in [Scribe assist by Sandro Hawke]

Jeff Pan: mustunderstand is a nice idea to allow users to specify intended semantics...

Alan Ruttenberg: is it the case that a mustunderstand on anything, then reasoners may not understand the semantics

Motivations

Alan Ruttenberg: lets consider motivations

1: one wants to use editing tools

Vipul Kashyap: Cool!


Sandro Hawke: suggest people give feedback to bijan on the general scheme

Ivan Herman: aestetic comment - word annotation is more what alan rector was describing

Ivan Herman: mustunderstand is not an annotation

Jeremy Carroll: Ivan didn't understand mustUnderstand ?!
Joanne Luciano: It's reminds me of C++ (?) preprocessing if I"m remembering correctly

Sebastian (guest): any tool that finds something strange could just say I do not know what to do with it... he likes the structure

Jeremy Carroll: The C preprocessor is, in many ways, too powerful ... give them enough rope ...

Boris Motik: useful to group certain types of properties into annotation or extension.... not sure that this should be in the ontology.

Boris Motik: this may be worthy of putting in a separate document

about to move on to user facing documents (and hoping for test discussion to come)

Straw Poll

Ian Horrocks: rich annotation mechanism but without notion of mustunderstand

most people agree a good idea

Achille Fokoue: +1 good idea
Joanne Luciano: +1 good idea

(jeremy objecting and, steve battelle abstained

that was for the general mechanism without semantics

Sandro Hawke: Jeremy is the only person not generally supportive of a rich annotation mechanism (ignore MustUnderstand issue)

now general idea with flagging semantic intention

Achille Fokoue: +1 good idea

good - 13

Joanne Luciano: +1 good idea

count good increased to 14 includes joanne

Joanne Luciano: :-)

discussion about what the vote was...

some kind of decorating mechanism of the existing syntax that would indicate a semantic change

PROPOSED: decoration of existing syntax as a way to make a syntactic change

revoting (guest):

Achille Fokoue: +1
Joanne Luciano: +1
Achille Fokoue: +1
Zhe Wu: +1
Joanne Luciano: +1
Sandro Hawke: rerun -- not counting observers....

in favor 14 (including the 3 remote participants)

against - pfps, sandro, alanrut - 3 total

abstain - hp

we could consider adding a swrl extension syntax to this proposal

Alan Ruttenberg: this may be out of scope

Joanne Luciano: Please note - I have to get on another conf call at 1630; I will monitor the call, but announce loudly if you move to Testing. I want to participate in that discussion if possible.
Joanne Luciano: Monitor via the chat - need the phone for th eother conf call.
Sandro Hawke: Add a hook for user-defined extensions.
s/Add/Boris (guest): Add/ [Scribe assist by Sandro Hawke]

feedback that it is reasonable to continue developing this

Joanne Luciano: still on chat though!
Alan Ruttenberg: What worries me is that you can have an OWL document that doesn't look like an OWL document. [Scribe assist by Sandro Hawke]
Jeremy Carroll: http://lists.w3.org/Archives/Public/public-owl-wg/2007Dec/att-0080/UFDTF_overview2.pdf

(Scribe changed to Giorgos Stoilos)

User Facing Documents

Slides for this session: Media:wallace-f2f1.pdf

Evan wallace is presenting the status of User Facing Documents

...documents that will help users into owl 1.1

...like guide, overview, reference

Evan Wallace: work mainly volunteered

...should these documents be produced as part of the spec?

...what syntax to use for the examples, different users have different preferences...DL syntax

...abstract syntax, etc

Evan Wallace: e.g. some docs use the DL side, while others use, like the Reference use a Semantic Web side (meaning RDF)

no much progress has been done

uli2 (guest): My (unfinished) tutorial with multiple syntaxes inline: http://www.cs.man.ac.uk/~bparsia/2007/owltutorial/

preference in producing an overview doc that is between OWL 1.1 overview and OWL overview

Sandro Hawke: (rather contovercially) I hope the Semantic Web survives RDF. [ That is, the goals of Semantic Web are important. RDF may not be the best way to meet those goals. I hope those goals are met, even if it mean moving beyond RDF. ] [Scribe assist by Sandro Hawke]
Deborah McGuinness: looking at the overview for 1.0, http://www.w3.org/TR/owl-features/

Bijan Parsia: is working in a way to choose to preview an example in the syntax of your choice

Deborah McGuinness: that overview suggestion might be drop section 1, and drop it from organizing section 2

Deborah McGuinness: looked in OWL 1.1 overview

Jeremy Carroll: a question is how much of the old docs we will use or start new ones

Deborah McGuinness: my comments were on starting from owl 1.0 overview
Deborah McGuinness: (and integrating in the owl 1.1 overview diff info)

Jeremy Carroll: do we want to extend the owl1.0 docs?

Bijan Parsia: oposes to extending the owl 1.0 docs. Finds them confusing

...don't thinks that good "tutorials" could be written within the WG

Bijan Parsia: if people want to go forward then he proposes something like RDF Primer

Ian Horrocks: thinks that an entry doc is very important and usefull

Bijan Parsia: what about the homepage?

...contains motivation, intro, etc

Michael Smith: homepage could also be improved to serve as a better intro doc

Zhe Wu: i'd like to see a doc with a complete list of new vocabularies and pointers to examples and semantics

Alan Ruttenberg: people are not learning OWL from the docs. Use them as refs rather than intros

Joanne Luciano: It would be good to take a poll (if one's not been already) to see objectively how people are learning OWL.

Bijan Parsia: exaplain some problems related to w3c for updating the docs

Bijan Parsia: proposes changing license on old OWL 1.0 UFD to allow derivatives [Scribe assist by Jeremy Carroll]
Bijan Parsia: this would allow (not this WG) to support the old docs (i.e. publish new versions outside this space) [Scribe assist by Jeremy Carroll]

Vipul Kashyap: agrees with alan rut

Vipul Kashyap: would like to have domain specific examples [Scribe assist by Jeremy Carroll]
Vipul Kashyap: how do we decide what goes where W3C or outside? [Scribe assist by Jeremy Carroll]

Bernardo Cuenca Grau: agrees with bijan. Why does educational material go to rec?

Uli Sattler: what about updating old docs with links to new matterial

Deborah McGuinness: don't see how this could be done

Sandro Hawke: explains a way

Vipul Kashyap: Why not?
Vipul Kashyap: I mean why should educational material/use cases/requirements not be part of the rec track?
Vipul Kashyap: I would like some clear guidance and criteria from W3C
Vipul Kashyap: Just forwarded Michel Dumontier's response to the OWL WG mailing list

Alan Ruttenberg: asks for a clarification on sandros example

Jeremy Carroll: RecTrack document means that author gets acknowledgement as W3C Document author, which in turn should mean more commitment towards the work. [Scribe assist by Pascal Hitzler]
Deborah McGuinness: +1

Evan Wallace: a plain language doc that could be used by non-experts is very good

Vipul Kashyap: Jeremy's response is "content independent"
Vipul Kashyap: Doesn't help me decide either way

Bijan Parsia: I am not highly against rectrack docs but more in favour for notes

Ian Horrocks: put the rectrack non-rectrack aside and think about the docs

Ian Horrocks: it seems from today that overall docs are not very good

Ian Horrocks: come again to the question whether starting fresh docs or extending old ones

Ivan Herman: has found guide docs of various groups very helpfull, like XML schema

Ivan Herman: if these docs have the blessing of the group then this is much better

....producing similar docs for the community would be good

Alan Ruttenberg: do we agree that we need a reference doc

Achille Fokoue: +1
Uli Sattler: ivan, if they are notes, they will still have the blessing of the WG?

Deborah McGuinness: because there are problems with existing ones does not mean we have to start with new ones

Bijan Parsia: proposes a fresh "primer" doc as a replacement of overview and guide

PROPOSED: To meet our charter deliverable of covering the intent of 'Overview' and 'Guide', we'll publish a new 'Primer' (written largely from scratch).

Joanne Luciano: +1 I like the primer idea
Joanne Luciano: How do we evaluate what we do (in general)?

James Hendler: asks about where the specification of OWL Full would go. Does not see it in OWL 1.1. functional syntax

Jeremy Carroll: agrees with jim. It would be helpfull to have a doc which explains to non-experts features of owl full

Evan Wallace: test
James Hendler: gives an example of inverseFunctional DatatypeProperties [Scribe assist by Giorgos Stoilos]
Jeremy Carroll: http://www.w3.org/TR/owl-ref/#InverseFunctionalProperty-def
Jeremy Carroll: jim's question is where would such text go if we do not have a document like OWL Reference
particularly (guest): [Scribe assist by Jeremy Carroll]
NOTE (guest): Because in OWL Full datatype properties are a subclass of object properties, an inverse-functional property can be defined for datatype properties. In OWL DL object properties and datatype properties are disjoint, so an inverse-functional property cannot be defined for datatype properties. See also Sec. 8.1 and Sec. 8.2. [Scribe assist by Jeremy Carroll]
Ian Horrocks: maybe we will decide to have such a documents (like the reference) [Scribe assist by Giorgos Stoilos]

Bijan Parsia: functional syntax must not change since it is the formal specification

PROPOSED: To meet our charter deliverable of covering the intent of 'Overview' and 'Guide', we'll publish a new 'Primer' (written largely from scratch).

Jeremy Carroll: To meet our charter deliverable of covering the intent of 'Overview' we'll work from OWL OVerview 1.0
Achille Fokoue: 0
Jeremy Carroll: To meet our charter deliverable of covering the intent of 'Guide', we'll publish a new 'Guide'
Jeremy Carroll: To meet our charter deliverable of covering the intent of 'Guide', we'll work from OWL Guide 1.0
Vipul Kashyap: I need a clarification
James Hendler: (can each of the things we are being asked to strawpole on be put up one at a time? - and I cannot see IRC from before joining, of course)
Vipul Kashyap: Perhaps working towards a document set like:
Vipul Kashyap: An introductory document between OWL 1.1 Overview and OWL Overview from Rec. (without the species of OWL emphasis)
Vipul Kashyap: A document intended as a language reference written in plain english
PROPOSED-1 (guest): To meet our charter deliverable of covering the intent of 'Overview' and 'Guide', we'll publish a new 'Primer' (written largely from scratch). [Scribe assist by Sandro Hawke]
Vipul Kashyap: Requirements with traceability
PROPOSED-2 (guest): To meet our charter deliverable of covering the intent of 'Overview' we'll work from OWL OVerview 1.0 [Scribe assist by Sandro Hawke]
Jeremy Carroll: no not really (to jim)

Peter Patel-Schneider: Aparently we should have 3 proposals: i) old docs, ii) fresh docs iii) prime proposal (bijan's)

James Hendler: wish I'd joined call earlier - incremental seems a lot less work than starting from scratch

PROPOSED: Refresh the old documents (otherwise, start mostly from scratch).

straw poll: YES=refresh docs NO=start new ones.

James Hendler: but no way to say yes to some docs and no to others? shouldn't we do this doc by doc?

Ian Horrocks: lets go doc by doc

Vipul Kashyap: Forwarded Christine's response to the OWL WG

straw poll on =overview=

James Hendler: overview = YES

PROPOSED: 'Overview' requirement from charter to be met by cleaned up and expanded-as-needed version of 2004 OWL Overview

Elisa Kendall: +1
James Hendler: +1
Achille Fokoue: 0
Zhe Wu: +1 (like to see delta)
Vipul Kashyap: +1
Joanne Luciano: 0 (just rejoined)
Sandro Hawke: pro in room - 4
Vipul Kashyap: +1 to start from scratch

votes for no in room - 9

Sandro Hawke: con in room - 9
Ian Horrocks: essentially a tie.... [Scribe assist by Sandro Hawke]
James Hendler: I VOTE YES
Elisa Kendall: +1

Ian Horrocks: people from the call are confused on what YES/NO choices meant. New poll is performed

Zhe Wu: +1
Joanne Luciano: +1

count on room: 3

Vipul Kashyap: +1 for NO

total for yes: 7

Achille Fokoue: abstain

votes for no=12 (11 + vipul)

Vipul Kashyap: OK
Vipul Kashyap: -1 then

PROPOSED: 'Requirements' requirement from charter to be met by cleaned up and expanded-as-needed version of 2004 OWL publication

next doc to poll =requirements=

voting for yes:

Achille Fokoue: 0
Ian Horrocks: Yes mean keep current document and warm it up. [Scribe assist by Sandro Hawke]
Zhe Wu: 0
Vipul Kashyap: -1

count on the room: 2

James Hendler: -1

voting for no

Elisa Kendall: -1
Joanne Luciano: +1 voitn for no

room (guest): 12

James Hendler: so it's not just the phone that is confused :-)

PROPOSED: 'Formal Specification' requirement from charter to be met by cleaned up and expanded-as-needed version of 2004 OWL publication

next doc =Reference=

James Hendler: +1 for reference

Starting vote from YES

Zhe Wu: +1
Elisa Kendall: +1
Achille Fokoue: 0

PROPOSED: 'Descriptive Specification requirement from charter to be met by cleaned up and expanded-as-needed version of 2004 OWL publication

Sandro Hawke: (skipping Formal Spec because it's not user facing)

count yes (refresh) in the room: 4

voting for no

Joanne Luciano: +1 start fresh
Vipul Kashyap: -1

count in room for no: 13

PROPOSED: 'GUIDE requirement from charter to be met by cleaned up and expanded-as-needed version of 2004 OWL publication

James Hendler: +1 yes for Guide
Achille Fokoue: 0
Elisa Kendall: +1

voting for yes:

Zhe Wu: +1

room for yes: 2

Vipul Kashyap: -1

voting for no

Joanne Luciano: +1 do new!

room for no: 13

James Hendler: but this means we cannot do incremental?
Peter Patel-Schneider: rough "page size" for Overview 14 - Reference 50 - Guide 38
Deborah McGuinness: An introductory document between OWL 1.1 Overview and OWL Overview from Rec. (without the species of OWL emphasis)
Deborah McGuinness: from evan
Vipul Kashyap: +1

Ian Horrocks: maybe not have a poll on evan's suggestion (above) since it is currently not clear

Deborah McGuinness: ha ha from joanne
Joanne Luciano: I want to stay!

test cases

Jeremy Carroll: explains some ways for doing tests

...every feature in the spec must have a test

Joanne Luciano: both are important

Jeremy Carroll: in owl test was a normative doc

Ivan Herman: not in sparql

James Hendler: note that to be able to leave PR, one must document that every feature is implementable, and the tests are a way to do that
James Hendler: +1 to postponing the decision

Ivan Herman: don't need to decide now about normative or non

Alan Ruttenberg: put test cases on wiki

Sandro Hawke: http://www.w3.org/2007/OWL/wiki/Test_Case_Experiment

Ian Horrocks: what will happen with existing test, will they be on the wiki

Joanne Luciano: response to alanrec - would have to update the tests!
James Hendler: do we have any commitment on archivability of the wiki?
Sandro Hawke: yes
James Hendler: and can it be frozen so it cannot be changed after some point (i.e. something that goes to Rec shouldn't have a "live document")
Sandro Hawke: test cases on wiki -- Sandro coding, Bijan as user, AlanRut, Jeremy

ACTION: Sandro to develop scripts to extract test cases from wiki, coordinating with Bijan, Jeremey, AlanRut.


Joanne Luciano: do we view test cases as sameas evaluation?
James Hendler: we phone folks just got cut off - meeting room left the wiki...
Jeremy Carroll: (meeting adjourned)
Jeremy Carroll: something went wrong with phone
Sandro Hawke: We got hung up on.....
Zhe Wu: i can hear someone typing
Jeremy Carroll: but we decided to adjourn
Evan Wallace: Zakim was cut off because we went past our scheduled time

Session 5 (Day 2, 09:00 - 10:45)

The text of this section is automatically included from F2F1 Minutes Session 5. Edits should be done there.


(Scribe changed to Jeff Pan)


Alan Ruttenberg: Major issue seems to be whether to use xsd datatype semantics

Datatypes

Slides for this session: Media:sattler-f2f1.pdf

Joanne Luciano: Alanr, let's meet when you get back

Uli is presenting

Joanne Luciano: are we starting with Issue 25 as in the agenda?

OWL DL does not support user defined datatypes

Uli Sattler: users want to represent intervals

... and comparisons

Ian Horrocks: slides available at http://www.cs.man.ac.uk/~horrocks/owl1.1-datatypes.pdf

... in OWL DL no inverse functional datatype properties

... not to mention composite keys (not even OWL Full supports this)

Boris Motik: we might want to keep the unit mapping out of TBox

Jeremy Carroll: second

Sebastian Brandt: there are real world examples

... that we need datatype mapping in the TBox

Bijan Parsia: both needed

Uli Sattler: we have examples of seeing class subsumption checking based on datatype constraints

Carsten Lutz: it is difficult to choose one standard set, e.g. covering integers, rational, +, *, ...

Uli Sattler: as many as possible

Jeremy Carroll: each simple example is easy

... but have concern on having all of them, which makes it hard

Bijan Parsia: Sebatian's use case: http://www.w3.org/2007/OWL/wiki/N-ary_Data_predicate_use_case

Sebastian Brandt: combining DL and data values are important and useful, there are many tasks that you could not solve if you treat datatypes externally

Alan Ruttenberg: do we want to detect the problematic cases?

Joanne Luciano: what does alan mean by "detect"?

Jeff Pan: there are existing works on datatype groups, a mechanism is already there, see http://www.websemanticsjournal.org/papers/20050811/document.pdf

Thomas Schneider: Uli has just added "[Alan] add support to check whether this mechanism (second item of '3.') has been used 'safely'". Does this help?

... even in OWL DL, freely combinations are not possible, e.g. transitive properties are not allowed to used in number restrictions

Alan Ruttenberg: I mean during species validation, for example. Or via declarations of what features are used and flagging incompatible combinations

Jeremy Carroll: what happen if data in the user databases having both integers, rationals + and * ...

Michael Smith: link again http://www.w3.org/2007/OWL/wiki/N-ary_Data_predicate_use_case

Boris Motik: we need some datatype profile

Carsten Lutz: second boris point

Jeff Pan: two points: 1) profiling is a good idea, there have been work there such as datatype groups

... and we could provide a list of feasible datatype groups

2) if users have integers, rationals + and *, we could simply have type promotion, promoting integers into rational, and it is still decidable, see http://www.w3.org/TR/swbp-xsch-datatypes/ and http://www.w3.org/TR/xpath20/#promotion

Alan Ruttenberg: maybe we could have a stroll poll on this

Bijan Parsia: we all agree that some sort of datatypes are needed, no matter in OWL or RIF

... many of our cases cannot be addressed by RIF

Jeremy Carroll: transitive issue is different

Bijan Parsia: linear polynomial (in-)equations over the reals or cardinals with order relations,
Bijan Parsia: nonlinear multivariate polynomial (in-)equations over complex numbers,
Bijan Parsia: (from the racer manual: http://www.sts.tu-harburg.de/~r.f.moeller/racer/racer-manual-1-7-19.pdf )
Bijan Parsia: page 11
Bijan Parsia: See page 47 and 48
Bijan Parsia: e.g., (* real AN ) (AN of type real or complex)

Jeff Pan: besides Racer, an extension of FaCT (FaCT-DG) also supports n-ary and datatype groups

Uli Sattler: we could have some more general proposal, rather than specific ones

Bijan Parsia: we don't have to require all our implementors to implement everything, so we should be flexible somehow

Uli Sattler: the 4th point: easy keys

Markus Krötzsch: in foaf people use b-nodes rather than individuals, so the easy key might not solve the foat problem

Bijan Parsia: What I meant: It's a bad idea to, in committee, to significantly and somewhat arbitrarily increase the implementation burden. But without adding a hook, implementors *can't* (compatibly) experiment
Bijan Parsia: So, let's add the hook and be cautious about how we fill in the hook

stall poll 1: many +1, no -1, four 0

s/stall/straw

straw poll 2: (all) +1

straw poll 3 (about 2-b): many +1, two (conditional) -1, six 0

straw poll 4 (n-ary datatype): twelve +1, six -1, five 0

straw poll 5(easy key): 22 +1, one -1

Boris Motik: one profile proposal: a set of default profiles and allowing users to have arbitrary profiles

Boris Motik: or people would be able to define their own profiles

Another go, boris' profile: a fixed set of profile and also allowing people to define their owl profiles

alanr's proposal: a fixed set of profile

Bijan Parsia: Note the current support for unary datatypes is already fragmenty: http://spreadsheets.google.com/pub?key=pTmcCXR-dV6RpTEPxB0O-DQ

straw poll on profiling on datatype: eighteen +1, four 0

Thomas Schneider: dmitry tsarkov introduced himself ...
Thomas Schneider: ... email: tsarkov@cs.man.ac.uk

scribers should clean up yesterday's minutes by next telecon

(by IanH and no objections)


Session 6 (Day 2, 11:15 - 13:00)

The text of this section is automatically included from F2F1 Minutes Session 6. Edits should be done there.



Ian Horrocks: We now have Zakim connected for those who want to dial in.

OWL DL and OWL Full

Slides for this session: Media:pfps-f2f1.pdf (pp. 1-3)

Peter presenting


Here's a brief description of how model theoretic semantics works

Peter Patel-Schneider: OWL DL has a fairly straightforward take on this

Peter Patel-Schneider: OWL Full and RDF take a slightly weird take on this

Peter Patel-Schneider: wherein properties and classes live in the world with real objects

Peter Patel-Schneider: Here are the differences between OWL DL and Full semantics

See "Two Model Theories" slide

Peter Patel-Schneider: things like rdf:type and owl:Class are not in the world in DL but are in Full

Alan Ruttenberg: In OWL DL Universe what is the status of Ontologies?

Peter Patel-Schneider: There is a separate place for them because of annotations

Peter Patel-Schneider: This description is about the specification and not practice

Bijan Parsia: The things in the OWL Full universe are in there with a theory

Peter Patel-Schneider: None of this matters in some sense

Peter Patel-Schneider: What matters is the behavior which results

Peter Patel-Schneider: ...such as entailments

Peter Patel-Schneider: Differences: It's possible to make assertions about the OWL vocabulary that change their interpretation

Slides for the rest of this session: Media:carroll-f2f1.pdf

Jeremy to take over presenting

Alan Ruttenberg: question about the intention of compatibility to be entailments of DL and Full be identical

Jeremy Carroll: for me the whole point is to get compatibility with RDF

Jeremy Carroll: A goal is "least surprise" for users of RDF when using OWL

Jeremy Carroll: OWL annotations are intended to behave as RDF annotations

Alan Ruttenberg: There are implications for RDF annotations that users may not be aware of

Alan Ruttenberg: I want to make a distinction between usage and consequences of the semantics

Bijan Parsia: I don't understand what you mean by RDF triple-by-triple semantics

Jeremy Carroll: In the OWL 1.0 semantics there are correspondence theorems between OWL Full and DL Semantics

Jeremy listed Issues related to the FULL and DL differences

such as 63, 76, 81, 69, 72, 55, 73

Jeremy Carroll: Do we want to allow semantic subsetting for fragments

Bijan Parsia: If we are going to support OWL Full do we need to support the full RDF umbrella

Joanne Luciano: He said something about if he wanted to reproduce what is in Jena, he'd like to have that info available to know what to reproduce

Bijan Parsia: described in Jeremy presentation

Jeremy Carroll: The semantic of RDF reification are essentially none

Bijan Parsia: There exists somewhere in the known universe a Statement that includes: S, P, O

Jeremy Carroll: There is no clear statement in the specs for how reification can work interoperably from system to system

Bijan Parsia: In the OWL full situation you have to interpret the reification syntax somehow

More discussion about how this can be done

Jeremy Carroll: Punning

In some peoples mind the web arch specifies that a URI corresponds to a single meaning

Punning is weaker than OWL Full because it violates this principle

Jeremy Carroll: this seems to cause user confusion

Mapping rules

In my view, the mapping rules were the hardest part of the OWL Rec

Jeremy Carroll: The drivers behind the mapping rules in OWL 1.1 are different

Jeremy Carroll: ...and this will lead to considerable change and probably

Boris Motik is speaking

Jeremy Carroll: ...issues later on.

Boris Motik: In my opinion many of these problems are the result of

Boris Motik: ...shoe-horning everything in the same universe.

Point for discussion later:

Joanne Luciano: please distribute (and reference here for later). which sldie # of URI / slide ref
Joanne Luciano: \me Thanks Peter.

Boris Motik: if we came up with an OWL Full that has a clean model theoritic framework

...then we could fix this.

Alan Ruttenberg: This would be a smaller OWL Full?

Bijan Parsia: Punning was intended to meet the goals of Full at least quarter way

Peter Patel-Schneider: The dogma in this case is the same syntax extension of RDF

Bernardo Cuenca Grau: The people who like OWL Full should really come up

...with features for OWL Full that they like and use

...Then we could do some research.

Ian Horrocks: The point I wanted to make was how much of this proposed

...work will be part of the work of this WG?

Boris Motik: Cleaning this up would be a huge accomplishment for this group.

Alan Ruttenberg: To my mind, it's not clear that cleaning up OWL Full is desirable to

... the Full/RDF community.

Jeremy Carroll: Dropping the comprehension principles seems like the

... smallest change that would be of value.

Alan Ruttenberg: Is this in scope for our group? Strictly speaking I don't think so.

Ian Horrocks: This kind of work just isn't in scope.

Bijan Parsia: Form an OWLED task force to look at this.

Alan Ruttenberg: We need to have a discussion about what compatibility means.

Alan Ruttenberg: If we allow OWL Full semantics changing that will affect backwards compatibility

Discussion of semantic fragments

Alan Ruttenberg: we have a delta now in the sublanguage entailments

Bijan Parsia: finding some delta that makes sense that makes the languages

...as close as possible would be a good thing.

Ian Horrocks: If we are comfortable with this semantic subsetting then

... we should be happy with the Full - DL differences

Ian Horrocks: One slight difference in Jeremy's proposal would be allowing

... more syntactic freedom but actually reducing the entailments

... by removing the comprehension principles for e.g.

Jeremy Carroll: HP might be happy with such a result if it is consistent

... with some broader framework.

Jeremy Carroll: There are easy bits in the OWL 1.1 language.

... getting those bits working are a bounded and achievable task.

Bijan Parsia: My experience is that users are concerned about not

... being able to process large numbers of RDF graphs

...with DL reasoners.

... Features like punning improves this situation.

Ian Horrocks: I wonder how hard it would really be to extend the status quo

... with some acceptable differences.

Ian Horrocks: This is a strawman for something that we could do.

Jeremy Carroll: I'd need to take this proposal back to HP before commenting on it.

Bijan Parsia: I would like us to keep the political and the user requirements seperate

ACTION: jeremy describe how punning and cardinality play poorly with each other


Jeremy Carroll: maybe we can say in the spec that punning is a concession to implementors, not a basic part of the semantics, that univocality is intended. [Scribe assist by Sandro Hawke]

Ian Horrocks: I'd like to see suggestions for concrete ways of moving forward to address these problems

Jeremy Carroll: Why don't we start with Qualified Cardinality Description?

Peter Patel-Schneider: Someone made comment that Qualified Cardinality Descriptions leads to non-monitonicity

... and I remember finding it believable

ACTION: pfps inform the WG on absurdity of QCR / OWL Full


ACTION: jeremy attempt Wiki sketch of QCR semantics OWL Full


Alan Ruttenberg: on concrete actions...

Alan Ruttenberg: How about we say: If you manage to game the system to have different meanings for a URI, you can't count on that [Scribe assist by Sandro Hawke]

... we have a set of options

Jeremy Carroll: a suggestion that Jeremy concentrate on OWL Full

... Semantics and drop out of User Facing Documents

Alan Ruttenberg: Any other specific proposals?

Ian Horrocks: Let's try and extend where are now and see where we end up.

Alan Ruttenberg: When do we evaluate when this approach is failing

... so that we can try another approach?

... I want to have some ideas about where we would go if this

... doesn't work.

Jeremy Carroll: We have had two variants proposed today.

... Sacrifice backwards compatibility and work towards 1.1

Bijan Parsia: We are spending a lot of time on this.

... I would like to know how much interest in this WG

... with Full compatibility.

Sandro Hawke: If there were a task force, who would be on it? -- Alan, Jeremy, Sandro
Jeremy Carroll: variant 2 - peter - drop same syntax requirement, and allow OWL 1.1 DL to have different syntax from RDF [Scribe assist by Jeremy Carroll]

Stawpoll

How many people want to use OWL Full for 1.1?

Joanne Luciano: 2nd question... +1 (not listed yet)

Jeremy rephrase: When using 1.1 do you want to use Full semantics?

Sandro Hawke: Q1- Are you a potential customer for OWL 1.1 Full -- you'll be using the document
Sandro Hawke: customer or reseller
Joanne Luciano: Q1 No.

Q1:

5 yes in room
15 no
Deborah McGuinness: jim would also be in the positive count for that question

q2 Are you a potential customer for Bijan's description of patch-up rules?

Sandro Hawke: Q2- Are you a potential customer/reseller of a specification of techniques for translation RDF graphs (in the spirit of OWL Full) to OWL 1.1 DL
Sandro Hawke: Q2- Are you a potential customer/reseller of a specification of techniques for translating RDF graphs (in the spirit of OWL Full) to OWL 1.1 DL
Joanne Luciano: Q2 yes
Joanne Luciano: Q2 +1

many in favor

Sandro Hawke: Q2 yes except for 2 abstainers


Session 7 (Day 2, 14:00 - 15:45)

The text of this section is automatically included from F2F1 Minutes Session 7. Edits should be done there.


RIF and OWL WG Collaboration

Alan Ruttenberg: there is a proposal to have a joint OWL & RIF task force

Alan Ruttenberg: ... peter is there. is there anyone else?

Alan Ruttenberg: ...uli is a second.

Sandro Hawke: I may sort of be on it for both

Bijan Parsia: I am liason to RIF and will continue to be


Fragments - OWL Prime

Slides were presented by Zhe Wu remotely, using Oracle conferencing software

Slide: Agenda

Slides for this session: Media:zhe-f2f1.pdf

Ian Horrocks: slides just sent to public-... list

Slide: Oracle 10gR2 RDF

Some technical difficulties continued w.r.t slide presentation

Zhe Wu: many ways to insert data.

Zhe Wu: ...in 10r2 we also support some inferencing and rules. we use forward chaining approach

Zhe Wu: ...also query using a SPARQL-like syntax

Zhe Wu: ... this was all in 2005

Slide: 11gR1

Zhe Wu: this year new release with new features. faster loading, owl reasoning with proof generation

Zhe Wu: ... overhauled performance w.r.t. load and query

Zhe Wu: ... just recently added Jena / Oracle adapter

Zhe Wu: ... joint with HP

Slide

Zhe Wu: subset of owl is supported

Uli Sattler: i'm curious about what scalable and efficient means

Zhe Wu: i will show some numbers later

Zhe Wu: ... re: what is supported - forward chaining rules implementation for fast query answer

Slide: "Why?"

Zhe Wu: ... conclusion in ISWC 2006 paper was that existing reasoners had problems with large ABox data

Slide 7: OWL subsets supported

Zhe Wu: rdfs++ added as a "minimal" extension to RDFS

Zhe Wu: ...owl prime, what is now proposed as rdfs 3.0

Slide: semantics characterized by entailment rules

Zhe Wu: owl prime has ~50 rules

Pascal Hitzler: does somebody know the exact literature reference for OWLPrime and can send it?
Pascal Hitzler: similar for OWLSIF - literature reference ...
Thomas Schneider: BTW The pdf with these slides can be found under http://ontolog.cim3.net/file/work/DatabaseAndOntology/2007-10-18_AlanWu/RDBMS-RDFS-OWL-InferenceEngine--AlanWu_20071018.pdf :)

Slide: Applications of partial dl semantics

Bijan Parsia: BTW, the survey paper mentioned in the talk on slide 9 is at: http://www.mindswap.org/papers/2006/survey.pdf
Bijan Parsia: It has more fine grained analyses, including in terms of AL, ALHF, SHIF, and SHOIN, on the one hand, and RDFS(DL), DL-Lite, EL++, and "non-tractable"
Bijan Parsia: It also discusses "repairable" OWL Full ontologies and (sketchily) how the non-repairable ones fall into OWL Full
Bijan Parsia: It's not at all clear to me how to map the analyses in that paper to OWL Prime (in part because I don't understand OWL Prime)
James Hendler: paper also took a DL approach to the world, the raw data showed the great bulk of the stuff out there, pre-change, was low expressivity RDF or RDF with a little OWL - it's where the RDF 3.0 proposal came from
Bijan Parsia: Uhm...I don't knwo what you mean by "raw data" and "great bulk"
Bijan Parsia: In fact, I don't see that anything I said had anything to do with what fell into RDFS or not
Bijan Parsia: The repair had mostly to do with the nominally owl full documents.
Bijan Parsia: In fact, if you look at table 2 and table 3, the second part of your assertion is at least questionable
Bijan Parsia: """Of the 307 OWL Full documents that can be patched, 63% become OWL Lite documents, and just 37% become OWL DL. Two observations can be made. First, The majority (91%) of the OWL Full documents (from Table 2) can be turned into a decideable portions of the languages by adding type triples. Secondly, the majority of RDFS documents (95%) can transition to OWL easily by adding type triples and use OWL vocabulary instead of RDFS vocabulary."""

Slide: support semantics beyond owl prime

Jeremy Carroll: question about example being supported directly in the future

Zhe Wu: exactly

Achille Fokoue: question about updates to abox

Zhe Wu: i'll get to that later

Slide 13: Advanced options

Alan Ruttenberg: question about time, can we focus on questions now

Zhe Wu: ok, i'll quickly browse remaining slides, then go to questions

Slide: implementation in rules

Zhe Wu: I want to stress that we did not handle one property at a time

Zhe Wu: I'll jump to query answering slide

Zhe Wu: ...that's all I wanted to cover, open for questions

Post Presentation Q & A

Ian Horrocks: the tractable fragments doc describes fragments with known database mapping. wondering why you didn't choose one of those

Zhe Wu: we started by asking existing customers what they needed. most told us they just needed simple extension into owl from rdf

Zhe Wu: ... pretty much the approach was driven by customers and need to implement efficiently

Ian Horrocks: but, customers said you needed something small (rdf + a bit) which is exactly what the fragments are. instead you chose a large fragment and implemented incompletely

Zhe Wu: so far, for those other fragments we have not found a complete rule set (except PD*)

Sandro Hawke: (I find the "small fragment" vs "large fragment" language very confusing, because I don't know what the metric is. large number of terms? large number of users? large implementation effort needed?
Bijan Parsia: Expressivity, I think

Uli Sattler: I want to echo ian and point out that you don't allow intersection, but a clever user would have it

Uli Sattler: ...and to be complete complexity becomes a problem

Uli Sattler: Complete with respect to one reasoning problem is sound with respect to another. ( In OWL? Really?? ) [Scribe assist by Sandro Hawke]

Alan Ruttenberg: they're not trying to be complete

Pascal Hitzler: the mentioned paper by ter Horst seems to be the following: Herman J. ter Horst, Completeness, decidability and complexity of entailment for RDF Schema and a semantic extension involving the OWL vocabulary, Web Semantics: Science, Services and Agents on the World Wide WebVolume 3, Issues 2-3, , Selcted Papers from the International Semantic Web Conference, 2004 - ISWC, 2004, October 2005, Pages 79-115.
Pascal Hitzler: ( http://www.sciencedirect.com/science/article/B758F-4H16P4Y-1/2/d039e4784b224e95aafca856ecfb1edb )
Pascal Hitzler: Keywords - Ontology; Semantics; Entailment; Completeness; Computational complexity

Boris Motik: echo ian, observes that fragments exist which can be implemented with a set of complete rules

Bernardo Cuenca Grau: i'm worried about soundness and worried about what "sound and complete" means here. I don't understand the semantics

Bernardo Cuenca Grau: ...b/c you haven't implemented the OWL semantics, you've chosen some of the OWL DL vocabulary

Zhe Wu: we do care about completeness, but don't consider it critical

Zhe Wu: ... completeness is evaluated w.r.t. query answering for some benchmarks, etc.

Bijan Parsia: From a spec perspective, this fragment seems to be *implementation* defined...which is a bit worrisome
Bijan Parsia: My test for this would be, without looking at thier rules or using your rule engine per se, can i write an implementation from a publically available description?
James Hendler: I would point out that DB communities tend to do language/sublanguage without model theories very comfortably

Jeremy Carroll: what I hear from customers echos Zhe's comments.

Jeremy Carroll: ...I note that much of the questioning is hostile

Alan Ruttenberg: I agree

Jeremy Carroll: that may be b/c much of the questioning is coming from members with different user groups

Bijan Parsia: I would disagree with the assessment of tone...is it even relevant?
Carsten Lutz: I would strengthen Boris claim and say that most (if not all) other fragments admit forward chaining, which is sound and even complete,
Carsten Lutz: and the rules are easily derived.
James Hendler: I also find that Web 3.0 companies, including the folks interacting with us on the billion triple challenge, also come from the perspective Zhe represents
James Hendler: http://ebiquity.umbc.edu/blogger/2007/12/06/the-semantic-web-billion-triples-challenge-at-iswc-2008/

Ian Horrocks: it wasn't intended to be hostile. I was trying to understand whether Oracle would be interested in more well understood and explainable fragments

Ian Horrocks: ...e.g., dl-lite which can be implemented in a database system, and also in a rule system

Ian Horrocks: DL Lite, not PD* [Scribe assist by Sandro Hawke]
Carsten Lutz: Same applies to EL++

Discussion of PD* soundness and completeness in a rule based implementation, which scribe didn't capture

James Hendler: fwiw, those fragments got little or no traction with the folks I consult for - they care about parallelizability and performance over the more understood stuf - their work is largely heuristic anyway

Ian Horrocks: the problem with PD* is that it doesn't implement a subset of OWL, it implements PD*

Jeremy Carroll: it depends on what you mean by fragment of OWL

Alan Ruttenberg: I hear interest in co-ordinating on database fragments with Oracle

Bijan Parsia: to standardize a fragment, we need a well defined specification that we can all understand

Uli Sattler: Zhe, I might have sounded hostile, which wasn't intended: some of us simply have a specific reading for certain words like "reasoner", and I couldn't see how this could be possible.
Uli Sattler: Zhe, also, if you want to see how IntersectionOf can be simulated with someValues and AllValues, ask Carsten.


IRC aside on specifications, definitions, and implementations

The following IRC conversation happened in parallel to the in room verbal conversation and some other IRC exchanges. It continued until Ivan the point in the minutes where Ivan requests an end to side conversations (just before Semantic Subsets)

Bijan Parsia: we need an *implementation independant* spec
James Hendler: What I am arguing for is that there are some important communities out there to whom the fragments they care about are not those tied to Uli's definition of reasoner
Sandro Hawke: hendler, people are not really paying attention to IRC.
Uli Sattler: Jim, I appreciate this -- but "reasoner" was used on Zhe's slides, and i simply wanted to know in which sense.
James Hendler: Bijan - agree with needing a spec, but I'd point out most programming languages get by just fine with operational semantics - in fact, since you implement Pellet in JAva, in a certain sense you're trusting that they get it right in some sense -
Uli Sattler: Jim, I guess what we would like to see is a consensus of what we mean by "Tool/reasoner X supports feature Y"
Bijan Parsia: First, I'm not saying anything about the specification style....but at the moment we don't have a clear spec. I don't know where to start other than by looking at Oracle's implementation
James Hendler: Uli, how do we show "Java" supports "begin/end loops"? that seems to be something in the real world that we could model for some (not all) of our work
James Hendler: this is the point!! thw Owl language features all have operational semantics that are good enough for many people in many situations - so when Oracle says we support X, why do we need more than that
Bijan Parsia: Second, there are differences between programming languages and ontology/data modeling languages. I hear your point, but find the analogy rather unconvincing.
Uli Sattler: Jim, I would never dream of trying to do this - but i would like to try to say what it means for a reasoner to support feature X
James Hendler: What I'm arguing is that RDFS 3.0, or OWL Prime, might be better looked at less as ontology languages (leave that to OWL DL) then as useful data analysis languages
Bijan Parsia: But I don't see why "useful data analysis langauges" don't need a clear spec
James Hendler: this is what my nose is rubbed in when I attend the Sem Tech conference and places like that
James Hendler: bijan - the question is what is the definition of a clear spec.
Bijan Parsia: Furthermore, model theory is pretty easy way to specify something...at the moment, no one has proposed anythign else
Zhe Wu: if there is a set of rules defined as those in RDFS spec, is that clear?
Bijan Parsia: Zhe, perhaps
Bijan Parsia: note that they are informative
Bijan Parsia: But I would be interested in looking at such
Zhe Wu: they may be informative, however, that is how most people understand semantics
James Hendler: but there are no model theories for many things, and model theory is not the only way to spec other things - like these rule-based examples
Uli Sattler: Zhe, we would call this "operational semantics" or such like and would be split about how clear this is
Bijan Parsia: Understand != spec
Bijan Parsia: Again, my test is can I write an interoperable implementation without looking at your implementation
Uli Sattler: +1 Bijan's inequality
Bijan Parsia: At least my first test
James Hendler: i.e. Inverse(A,B) IFF s A p -> p B s
James Hendler: seems like a fine definition of inverse
Zhe Wu: if we agree on a set of rules, then interoperability is not an issue
Bijan Parsia: Not at all since I don't know what you -> means
Bijan Parsia: Zhe, no
Bijan Parsia: Not clear at all
Bijan Parsia: For example, i might no use those rules *in* my implementation
Zhe Wu: using Hendler's example rule,
Bijan Parsia: I might want to use a very different technique
Zhe Wu: if we agree on that, then we are interoperable
Bijan Parsia: Is that rule controposable?
Uli Sattler: The reading of rules, for example, differ in whether you have contraposition or not
Bijan Parsia: Was it meant as <->?
James Hendler: Bijan, that is either easily defined, or can be left to philosophers trying to write PhDs, in the real world, lots og languages work this way - but if you want something better - okay, we'll use SCL
Uli Sattler: and whether you "apply" it to all named individuals or to *all* individuals
Bijan Parsia: hendler, that's not true
Bijan Parsia: But c'mon, that wasn't even a partial spec
Bijan Parsia: And it was of one of the easiest bits
Bijan Parsia: Inverse
Uli Sattler: so, I agree that your defintion of inverse seems clear, but when you want to implement it, there are questions coming up
Bijan Parsia: Consider complementOf
James Hendler: ok, KIF
Bijan Parsia: English would do
James Hendler: I agree with Zhe
James Hendler: complementOf not in RDFS 3.0 for precisely that reason
Bijan Parsia: It was in OWL Prime
Uli Sattler: Again, I find englisch often clearer than things like "->' or such like
Evan Wallace: Or did you mean CLIF from the ISO standard, Common Logic
James Hendler: English ok w/me
Bijan Parsia: In any case, I'm asking for a spec. We can beat on the spec and if we find problems we find problems
Bijan Parsia: If we don't we don't
James Hendler: but anyway, the point I'm making is not to oppose model theory - but the problem is to get the model heory right we have to put restrictions on the languge that some of us cannot live with easily
Bijan Parsia: I don't know that that's true
Uli Sattler: Jim, I disagree:
James Hendler: this is why OWL LITE is a subset of DL - not of Full, so there is no fragments for Full - which is what i often get asked for
Uli Sattler: Jim, model theory doesn't restrict things?
Bijan Parsia: I'm very skeptical about it, but I don't know because I don't know what the current fragment actually *is*
James Hendler: Uli, so we could define the language fragment based on other concerns and then define it via model theory - that doesn't bother me at all - I'd be fine with that
Bijan Parsia: But I'm open to being convinced otherwise...but I'm more convincable by a proof of concept (at least) than high level discussion
James Hendler: so Oracle has implemented OWL prime - what did I miss?
Bijan Parsia: Implementation != specification
Bijan Parsia: And this is true for programming langauges as well
Uli Sattler: Jim, what would you define via model theory? The fragment or its semantics?
James Hendler: Uli - whichever you want - I'm not going to need to read that document anyway ;-)
Uli Sattler: Jim, I think we simply disagree what it means to *implement* a fragment
Bijan Parsia: There are langauges defined by *specs* (including Java, Common Lisp, C, C++) and those defined by *implementation* Perl, Python
Bijan Parsia: (at least historically)
Bijan Parsia: So, frankly, I don't want to port Oracles implementation. That's probably not even legal
James Hendler: fine - I want a fragment of OWL that is defined by *specs*
Bijan Parsia: I want a specification sufficient for independant implementation
Bijan Parsia: But jim, if the specs happen to do it by model theory and capture the language you want, what do you care?
Bijan Parsia: If the specs are clear enough for me I don't necessarily require model theory ( though it helps so we can understand the relation to existing OWL specs)
James Hendler: bijan - the poiunt is I don't care - and I said that - what I care is what is in the fragment first, how to define it second
Bijan Parsia: How do you know what's *in the fragment* without a definitio of what the fragmetn is?
Bijan Parsia: What's the difference?
Sandro Hawke: hendler, please stop talkin on IRC.
James Hendler: Bijan - you're arguing circularly - but I can cut through it - I have created a wiki page with a description of exactly which language features I want to include - how to define it in a spec is something I'm happy to discuss
Sandro Hawke: Jim, we're talkin in the room now, and need to focus on this discussion in the voice channel, so no more chatter on IRC, please.

Fragments: (Tractable) Fragments and other Fragment Proposals

Bernardo Cuenca Grau presenting from slides in person

Ian Horrocks: Bernardo's talk in email and at http://www.cs.man.ac.uk/~horrocks/F2F-Fragments.pdf

Bernardo Cuenca Grau: motivation of owl-lite was easier owl. b/c owl dl and full are rich and complex.

Bernardo Cuenca Grau: ...problem is owl-lite is broken b/c it doesn't address interactions between constructors

Bernardo Cuenca Grau: most features held out of owl-lite can be recovered through "back doors"

Bernardo Cuenca Grau: existing document includes fragments which

Bernardo Cuenca Grau: .... are well understood, documented, etc.

Bijan Parsia: A precursor to OWL Lite giving some of the rationale: http://www.aifb.uni-karlsruhe.de/~sst/is/WebOntologyLanguage/harmelen.htm
Bijan Parsia: Er...precursor discussion

Bernardo Cuenca Grau: we don't expect users to go over recent literature on tractable fragments, so wanted a single document

Bernardo Cuenca Grau: most of the languages I will describe are "families" of languages, we decided to keep 1 from each

Bernardo Cuenca Grau: 1st is EL family

Bernardo Cuenca Grau: ...used in bio-medical already

Bernardo Cuenca Grau: stress that these fragments are not academic exercises, there are direct applications to existing ontologies

Bernardo Cuenca Grau: 2nd is DL-Lite family

Bernardo Cuenca Grau: ... designed for large number of instances in database technology

Bernardo Cuenca Grau: approach is similar to what zhe described, do work in tbox, then pass to database system for query answering

Carsten Lutz: reiterate bernardo, but contrast with zhe's approach. dl-lite change the ontology to use database technology, not change the database technology

Pascal Hitzler: would be nice to get a literature reference to OWLPrima - the description on the slides was not clear enough
Pascal Hitzler: I could find nothing on the web defining OWLPrime
Boris Motik: Pascal, pD* has been described here: http://www.springerlink.com/content/366474250nl35412/

Alan Ruttenberg: another difference is in oracle you can query for classes, in dl-lite only instances

Bernardo Cuenca Grau: you can do tbox reasoning, but designed for abox answering.

Bernardo Cuenca Grau: I picked the particular dl-lite language b/c it is between rdfs schema and owl dl

Zhe Wu: is there a scalable implementation of dl-lite? commercial tool?
Zhe Wu: Uli, what kind of tool? what is the scalability?
Bijan Parsia: Zhe, to the first, yes
Bijan Parsia: To the second, no
Bijan Parsia: QuOnto
Bijan Parsia: (Not yet)
Uli Sattler: Zhe, yes ther is, I think: search for Quonto
Uli Sattler: Zhe, it is as scalable as it can get:
Uli Sattler: Zhe, because it translates queries into SQL queries and leaves everything in the DB.
Carsten Lutz: Zhe, I understand that you would like to do forward chaining. A lot of fragments can be captured in a sound
Carsten Lutz: (and even complete) way with this technique. I would like to learn what is your idea of tractability and
Carsten Lutz: scalability. Is it forward chaining per se, or is it a rule set that does not produce too many new facts?
Zhe Wu: Carsten, the scability and performan requires are determined by the market.
Zhe Wu: Carsten, people are asking for hundreds of millions of triples and beyond

Bernardo Cuenca Grau: next is Horn-SHIQ

Bernardo Cuenca Grau: ...can reason without disjunctions

Bernardo Cuenca Grau: ...and low complexity for query answering

Bernardo Cuenca Grau: other fragments dlp as a bridge to rules

Bernardo Cuenca Grau: ... but it may be more "hacky" that horn-shiq

Bernardo Cuenca Grau: questions for wg

Bernardo Cuenca Grau: ....1 do we fix owl lite

Bernardo Cuenca Grau: ....2 does that mean select one of these fragments

Bernardo Cuenca Grau: ....3 or do we present a menu of fragments?

Bernardo Cuenca Grau: not in slides - do we want semantic subsets of owl full?

Bernardo Cuenca Grau: ....e.g., owl full versions of these fragments? do we care about complexity of the full fragments? about compatibility?

Ivan Herman: request to drop side conversations

Ivan Herman: ... and focus

Semantic Subsets

Alan Ruttenberg: little time, can we start with semantic subset of owl full?

Ian Horrocks: semantic subset means no change to syntax, but sanction smaller set of conclusions

Jeremy Carroll: example is pd*, which specifies what semantic rules are thrown away

Peter Patel-Schneider: pd* throws away *parts* of rules

Ian Horrocks: this is picky

Sandro Hawke: hendler, are you able to call on the phone?
James Hendler: sandro, no.
Joanne Luciano: hendler, type what you want us to speak for you
James Hendler: what kind of fragment?
Sandro Hawke: Alan is chairing this session.
Joanne Luciano: hendler, do you have access to the slides?
Joanne Luciano: to Hendler: fragments of OWL 1.1, which: are the result of years of research, have “nice” computational properties, are already supported by tools
Joanne Luciano: to hendler: cover most existing ontologies
James Hendler: But there are fragments which are not included that have all those things as well - Oracle Prime being a perfect example
Alan Ruttenberg: Jim, please call in if you want to participate
Joanne Luciano: to hendler: Fragment Goals: suggest possible fixes to OWL Lite, inform the OWL community about recent research results, help users & tool designers

Alan Ruttenberg: how comfortable are people with this type of fragment

Alan Ruttenberg: ... does anyone want to say this is a lousy idea.

Peter Patel-Schneider: yes, its lousy b/c you can be arbitrarily picky

Ian Horrocks: its a lousy idea b/c it blows away the idea of interoperability

Bijan Parsia: qualm that methodological design principles are "unclear"

Bijan Parsia: ...guidance for making decisions seem more arbitrary, a dangerous rat-hole

Bijan Parsia: ... would rather people say they are incomplete than building incompleteness into fragments

Jeremy Carroll: in response to ian, any semantic subsetting would need to be clear that it is a subset of spec and an explicit, agreed semantic subset

Jeremy Carroll: ...e.g., oracle and hp would agree on semantic subset and interop on at-least the semantic subset

Sandro Hawke: +1 Jeremy -- "incompleteness" is fine When It's In A Specified Fragment, that is implementated in multiple places, etc.

Alan Ruttenberg: if we call this fragment or conformance level, it seems useful

Alan Ruttenberg: ...that baseline entailments are necessary, but additional entailments may be ok

Bijan Parsia: if we shift from language fragments to reasoner conformance I'm more comfortable

Sandro Hawke: Bijan, "Reasoner Conformance" might be a more useful notion here than "Language Fragments".

Sandro Hawke: ...I have examples of people specifying this at a tool level.

Jeremy Carroll: i'd be happy with such a rewording. i don't see it as notable

Alan Ruttenberg: does such a distinction help others

some affirmation to alan in room

Zhe Wu: ?

Alan Ruttenberg: he said it would be useful to say we support same entailments

Ian Horrocks: more comfortable defining conformance that fragments

Ian Horrocks: and jeremy's suggestion sounds like standardising implementations
Alan Ruttenberg: Jim, you still there. Hard to follow the IRC. I can read what you write if you want to respond.

Bernardo Cuenca Grau: users are comfortable with incomplete reasoning. swoop offering rdfs reasoner as a choice is an example of this

Bernardo Cuenca Grau: ...more comfortable with that than trying to specify semantic subsets

Pascal Hitzler: +1 to bernardo
Pascal Hitzler: bernardo also stressed the importance of a clear semantics as reference ...

Jeff Pan: i agree with bernardo and others.

Jeff Pan: ... implementation does not specify fragment.

Boris Motik: i just looked at pd* , this seems like definition. I think it is a useful fragment if evaluated a certain way.

Ian Horrocks: i didn't say pd* was bad, that we'd be standardizing an implementation. it was a reaction to jeremey's comments on what hp and oracle might do

Sandro Hawke: owl is unique to me b/c it doesn't specify what the tools do, people read into that. specifying the tools would be useful. as a customer I expect that and would like it

Joanne Luciano: what's "pd*"?
Sandro Hawke: PD* is referred to in Zhe's presentation.
Sandro Hawke: (from Herman ter Horst)
Zhe Wu: ina: it is not just hp and oracle, owlim, allegrograph as well

Bijan Parsia: justifying discomfort - seems likely that over time fragments specified in such a way are likely to move

Bernardo Cuenca Grau: on sandro's comment - we should specify reasoning services

Bernardo Cuenca Grau: ... it's not in the spec for OWL DL. for fragments the services descriptions would be useful

Sandro Hawke: i don't know what the terms are, the market decides

Sandro Hawke: It should be customer driven. When they want to find on the shelf, those should be the things defined in the spec. [Scribe assist by Sandro Hawke]

Ian Horrocks: its difficult to imagine semantic subsets not drifting apart

Ian Horrocks: ... it has been a success for owl that interoperability is so good, considering

Jeremy Carroll: responding to standardizing tools - yes. there is value to user if they know different tools perform the same

Jeremy Carroll: ... this wg could provide appropriate conformance levels where vendors and user community come together

Jeremy Carroll: ... clear that motivations from academic community are useful, but they aren't the only motivations

Sandro Hawke: +1 Jeremy: there is real value to the customers in knowing that a set of products will all do (at least) the same thing. It would be a service to the community for this WG to provide that.

Alan Ruttenberg: no one is saying market is unimportant

Uli Sattler: clarification on user needs?

Jeremy Carroll: users need some sort of specification, but don't need to know behavior is exact

Alan Ruttenberg: I want to poll for consensus on how to procede

Joanne Luciano: +1

Sandro Hawke: i don't understand

Alan Ruttenberg: I want to know if people think these fragments are useful

Alan Ruttenberg: ... defined as a minimum set of entailments

Bijan Parsia: reasoners can conform to the language to different degrees

Ratnesh Sahay: subset of language + conformance level, is something similar to the way current languages (e.g) doing, like, Deprecated apis + core language( and specialized apis)
Michael Smith: subsets of entailments == conformance levels

Alan Ruttenberg: we should aim for something specified like pd*

Ian Horrocks: declarative...

Alan Ruttenberg: yes, declarative

Sandro Hawke: Q1 - The Working Group should (formally, precisely) define conformance levels, defining groups of reasoner which can do certain kinds of reasoning (all for a given OWL Fragment).
Sandro Hawke: Q1 - The Working Group should (formally, precisely) define conformance levels, defining groups of reasoners which can do certain kinds of reasoning (all for a given OWL Fragment).

Uli Sattler: we would later know e.g., what it would mean for a reasoner to conform to particular level?

Alan Ruttenberg: yes.

Jeff Pan: what does conformance level mean? is it in terms of benchmark?

Uli Sattler: provides example

Ian Horrocks: The Working Group should (formally, precisely) define conformance levels, defining minimum levels of inference that would be found?
Zhe Wu: q+

Carsten Lutz: degrees of incompleteness?

Ian Horrocks: The Working Group should (declaratively) define conformance levels, defining minimum levels of inference that would be found?

Alan Ruttenberg: degree of completeness

Alan Ruttenberg: ...fragments are syntactic fragments

Alan Ruttenberg: ...conformance levels are distinct

Sandro Hawke: Q1 - The Working Group should (declaratively) define (one or more) conformance levels, defining minimum levels of inference which would be performed (for a given OWL Fragment).
Achille Fokoue: yes if we are talking about a declarative way of defining minimum levels of inference

Jeff Pan: there might be difference between alan's and uli's suggestions

Alan Ruttenberg: distinction is unimportant now

Zhe Wu: when we, as a group define confromance levels, it is very useful to look at current market
Zhe Wu: including HP, Oracle, AllegroGraph, OWLIM etc.

Alan Ruttenberg: reads Q1 as above

Sandro Hawke: against - Jeff, Carsten, Ian
Achille Fokoue: +1 ( for a declarative approach)
Joanne Luciano: joanne raises hand
Sandro Hawke: abstain - none.
Sandro Hawke: BREAK.
Joanne Luciano: joanne lowers hand
Sandro Hawke: lots and lots of people raise their hands in favor.

Session 8 (Day 2, 16:15 - 18:00)

The text of this section is automatically included from F2F1 Minutes Session 8. Edits should be done there.


(Scribe changed to Uli Sattler)

Organizational Things and Scribing

Jeremy Carroll: has resigned from UFDT, but wants to cancel next monday?

Alan Ruttenberg: will arrange next UFDT

ACTION: on AlanR to arrange next UFDT meeting

Joanne Luciano: alan, contact me when you're back in town (and rested)

Sandro Hawke: has seen 7 sessions' minutes, currently 57 pages and asks how to read to accept them and asks the scribes, when cleaning them up, to add sub headers: syntax is "===" for sub headers

ACTION: AlanR to arrange next UFDT meeting

Michael Smith: asks whether to serialize shuffled subdiscussions

Sandro Hawke: yes, please disentangle

Joanne Luciano: please speak a little louder
Joanne Luciano: what did alanr just say?

Ian Horrocks: asks what to do with parallel discussions, esp. on the IRC

Sandro Hawke: keep them if they are relevant

Sandro Hawke: scribes finish cleaning up this wednesday

Jeremy Carroll: wants to see actions & resolutions in the minutes

Sandro Hawke: Yeah -- keep IRC threads in if they are topical.

Bijan Parsia: subgroups affected by discussions at F2F should update their documents with pointers to minutes

Joanne Luciano: I'd like to see things fleshed out a little in the minutes -

Jeremy Carroll: suggests to minimize effort on minutes

Joanne Luciano: add links and pointers of a few definitions

Alan Ruttenberg: asks for subjects for discussions

Joanne Luciano: raise hand

Bijan Parsia: non-OWL full issues with RDF mapping

Alan Ruttenberg: agrees with Bijan, mentions reification

Bijan Parsia: axioms annotation asserted versus reified

Alan Ruttenberg: wants to see both

Ian Horrocks: we already agreed that we should explore both assertions & reifications

Sandro Hawke: what about b-nodes and reification?

RDF Mapping Issues and Minutes (mixed discussion)

Bijan Parsia: can we discuss now some RDF mapping issues?

Joanne Luciano: raise hand

Michael Smith: has added such an issue wrt declarations

Bijan Parsia: you can't specify a signature for an ontology without using the elements of that signature in an axiom or a declaration (which requires owl11 terms)

Matthew Horridge: reports on user complaints regarding declarations

Michael Smith: the issue on this is Issue 89 http://www.w3.org/2007/OWL/tracker/issues/89

Joanne Luciano: asks for a summary sections of minutes and wants to discuss evaluation issues

Peter Patel-Schneider: disagrees with JLucianos suggestions: scribes should never paraphrase

Alan Ruttenberg: suggests to have summaries outside minutes

Ian Horrocks: suggests to post summaries on the mailinglist

Sandro Hawke: add links to presentations in minutes

Ian Horrocks: suggests clean up/mark up other material as well

Sandro Hawke: mentions that chairs could, if they wanted, blog meetings

Jeremy Carroll: doesn't want to do them

Sandro Hawke: or anyone else could blog meetings.... (ie summarize them).

Alan Ruttenberg: hasn't seen a lot about evaluation

Sandro Hawke: alanr, adenda+ F2F2 ?

Jeremy Carroll: wants to give 2 examples reg. OWL Full compatibility: (1) we have an OWL11 document with reified annotions, we save and modify it....

Matthew Horridge: do we discuss punning or declaredAs?

Bijan Parsia: SUBPROPERTYOF[op1,...,opn] expands to rdfs:subPropertyOf if OnlyOP(opi) = true for each 1 ≤ i ≤ n, and to owl11:subObjectPropertyOf otherwise;

Jeremy Carroll: is worried about (starts reading out from the text above)

Sandro Hawke: from http://www.w3.org/2007/OWL/wiki/Mapping_to_RDF_Graphs

Jeremy Carroll: there are various rules like this one, and they are the wrong ones

Bijan Parsia: understands why: if we have r subproperty of s, and then I add a composition, then this addition would lead to a different kind of serialization

Bijan Parsia: suggests that using different syntax for SubPropertyOf would solve this issue

Bijan Parsia: this is different from round tripping

Jeremy Carroll: suggests to have some form of switch that safes an ontology in OWL11, then we shouldn't expect it to be saved in an OWL10 format unless I require this explicitly

Matthew Horridge: asks whether the spec shouldn't specify this behaviour

Michael Smith: asks whether Jeremy wants tools to save ontologies only in OWL10 if explicitly asked to do so

Jeremy Carroll: observes a subtle relationship between the 2 OWL syntaxes

Ian Horrocks: comes back to AlanR' spoint, and points out that it would introduce nasty non-determinism wrt serialisation and that our n-ary disjointness axioms would cause trouble

Alan Ruttenberg: regards it as a bug to have these 2 possibilities for reading/serializing n-ary disjointness

Bijan Parsia: sees an issue with the mapping, we need to decide what to do with it: deal with it or not. And it would be nice to be clear on our decision in the spec and to have test cases.

Alan Ruttenberg: declarations fall into similar league

Matthew Horridge: disagree - we can throw them in/out

Michael Smith: points back to Issue 89

Alan Ruttenberg: asks whether we like declarations

Matthew Horridge: mentions that we can have both, declarations and roundtripping, but with a different mapping

Matthew Horridge: mentions discussions on the mailinglist

Boris Motik: explains that there are 2 readings of declarations. Declarations, possibly using rdf:type can and should be used for linting/simple syntactic check

Bijan Parsia: there are other use cases. [Scribe assist by Sandro Hawke]

Bijan Parsia: adds that we can also throw out some "used terms"

Boris Motik: wants to distinguish declaredAs from type. Since there is no notion of typing of RDF, things become problematic, especially with imports, e.g, do we need to re-declare when importing? In the owl10, there was no difference between "class" and "declaration"

Sandro Hawke: -Carsten

Alan Ruttenberg: there wasn't even a notion of an ontology containing an axiom

Bijan Parsia: there is something about documents and ontologies (how to get one from the other)

Jeremy Carroll: suggests to use lateral thinking to solve this: use a new way of imports, namely one where we put import statements at the top of our ontologies and then all declarations will be there!

Boris Motik: seems to agree that this will help tools - if I knew what the type of things are, I could use streaming mode

Bijan Parsia: if they come late, they can still be useful (eg to find typos), but they are most useful at the top

Jeremy Carroll: suggests that we can do this via searching & process imports first

Boris Motik: asks whether typed vocabulary will be obsolote - if yes, we can re-use it

Boris Motik: we can merge the notion of typing and declarations, but cleanly

Jeremy Carroll: wouldn't it make a difference wrt model theory

Boris Motik: no, it's all syntax

Matthew Horridge: we need orphaned entities rather than declarations

Michael Smith: paraphrases that we want to be clear whether rdf:type is a declaration or something else?

Boris Motik: can we add a class to an ontology without adding an axiom? Declarations are a way to mention an entity outside any axiom.

Alan Ruttenberg: asks whether in OWL11, can we have X owl:class Class?

Bijan Parsia: yes, it's in OWL Full, but it disappears in the OWL DL mapping and in the XML syntax

Sandro Hawke: wants to add next F2F meeting to agenda

Bijan Parsia: wants to see from Boris examples explicating differences and consequences of both solutions

Alan Ruttenberg: and we need to check our claims re. what appears/disappears in mappings

Alan Ruttenberg: wants to see backwards compatibility on the agenda

F2F2

Peter Patel-Schneider: F2F2 will be on April 3 and 4, in the Washington DC area, venue to be determined. OWLED might be in the area, but perhaps not. One possibility is to make use of NIST, but access is restricted

Joanne Luciano: where is Peter you talking about
Joanne Luciano: I might be able to host it at MITRE

Evan Wallace: access to NIST is a bit tricky, but only first time

Helooooo (guest): -) [Scribe assist by Joanne Luciano]

Peter Patel-Schneider: downtown DC or near to NIST are possible, too.

Peter Patel-Schneider: considers the possibility to move 1 day earlier to make AlanRector happier

Joanne Luciano: Who's the NIST person?
Joanne Luciano: hand up

Joanne Luciano: has mentioned MITRE

Peter Patel-Schneider: says that access at MITRE is even more difficult than at NIST. This time of year, the DC area will be extremely busy and thus we need to book Hotels early

Bijan Parsia: offers to make use of C&P rooms

Peter Patel-Schneider: reinforces the need to book hotels early

Peter Patel-Schneider: will come up with proposal together with Kendall Clark

Joanne Luciano: how many people?

ACTION: ppatelsc to tell us by 2 weeks where F2F2 will be

Alan Ruttenberg: wants to talk about backwards compatibility

Ian Horrocks: closes, thanks Sean Bechhofer for hosting

Sandro Hawke: ADJOURN
SW_OWL(F2F)6 (guest): 00AM has ended [Scribe assist by Zakim (guest)]