Teleconference.2008.01.23/Minutes

From OWL
Revision as of 12:42, 13 February 2008 by IanHorrocks (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

These minutes have been approved by the Working Group and are now protected from editing. (See IRC log of approval discussion.)

See also: IRC log



(Scribe changed to Doug Lenat)

Admin

Alan Ruttenberg: accept minutes from Jan 9

PROPOSED: accept minutes of Jan 9

Ivan Herman: 0
Peter Patel-Schneider: +1 and a BIG thanks to Ian for fixing the minutes!
Uli Sattler: ok
Rinke Hoekstra: +1 to accept
Ian Horrocks: +1
Doug Lenat: +1
Alan Ruttenberg: +1
Jeff Pan: +1
Bernardo Cuenca Grau: +1
Deborah McGuinness: 0 - abstain - missed meeting
Uli Sattler: +1
Michael Smith: +0, noting the minutes still contain queue management and zakim clutter
Ratnesh Sahay: +1

RESOLVED: accept minutes of Jan 9

PROPOSED: accept minutes of last week

Ivan Herman: +1
Ian Horrocks: +1
Doug Lenat: +1
Alan Ruttenberg: +1
Peter Patel-Schneider: +1, they are acceptable
Jeremy Carroll: +1
Bernardo Cuenca Grau: +1
Markus Krötzsch: +1
Rinke Hoekstra: +1
Michael Smith: +1
Zhe Wu: +1
Doug Lenat: +1
Jeff Pan: +1

RESOLVED: accept minutes of last week


Discussion (quick) of pending actions

Jeremy Carroll: Action 63 has, I believe, been closed

Alan Ruttenberg: Action 52: added test guidelines: link added with draft instructions. respond to this please

Uli Sattler: Action 61 is also done, I think
Ian Horrocks: I also believe that 61 is done
Deborah McGuinness: you said there is the option to document?

Proposals to Resolve Issues

Issue 8: as proposed (not clear how to do this, hence postpone)

Deborah McGuinness: are we not definitely documenting?

As per http://lists.w3.org/Archives/Public/public-owl-wg/2008Jan/0122.html

PROPOSED: close (as POSTPONED) Issue 8 (dataproperty chains) as per http://lists.w3.org/Archives/Public/public-owl-wg/2008Jan/0122.html


RESOLVED: close (as POSTPONED) Issue 8 (dataproperty chains) as per http://lists.w3.org/Archives/Public/public-owl-wg/2008Jan/0122.html

Peter Patel-Schneider: +1


Turning to Issue 15 (Ontologies should not be required to include a URI) as per http://lists.w3.org/Archives/Public/public-owl-wg/2008Jan/0019.html

PROPOSED: close (as RESOLVED) Issue 15 (Ontologies should not be required to include a URI) as per http://lists.w3.org/Archives/Public/public-owl-wg/2008Jan/0019.html

Peter Patel-Schneider: +1
Deborah McGuinness: are we doing anything to encourage naming ontologies?

Deborah McGuinness: We'd be better off with named ontologies, and should indicate it's a "best practice"; easier to track where they came from.

Jeremy Carroll: concern about further diversion from owl full and its family members.

Peter Patel-Schneider: we don't have to right now, we allow unnamed ones, so there is no need for serious concern about that

Alan Ruttenberg: we want imports, want synergies, so why not encourage it?

Alan Ruttenberg: if the imports task force shows unexpected divergence then we would have new information to revisit this issue [Scribe assist by Jeremy Carroll]

RESOLVED: close (as RESOLVED) Issue 15 (Ontologies should not be required to include a URI) as per http://lists.w3.org/Archives/Public/public-owl-wg/2008Jan/0019.html


PROPOSED: close (as RESOLVED) Issue 29 (User-defined Datatypes: owl:DataRange vs rdfs:Datatype) as per http://lists.w3.org/Archives/Public/public-owl-wg/2008Jan/0017.html (see also http://lists.w3.org/Archives/Public/public-owl-wg/2008Jan/0147.html and thread)

Peter Patel-Schneider: summarizing the issue: proposal to make owl datarange unnec. except for backwards compatibility

Peter Patel-Schneider: +1
Ivan Herman: +1
Doug Lenat: +1
Alan Ruttenberg: +1
Markus Krötzsch: +1
Uli Sattler: +1
Rinke Hoekstra: +1
Michael Smith: +1
Ian Horrocks: +1
Zhe Wu: +1
Jeff Pan: +1
Bernardo Cuenca Grau: +1
Deborah McGuinness: +1
Boris Motik: +1
Ratnesh Sahay: +1

RESOLVED: close (as RESOLVED) Issue 29 (ser-defined Datatypes: owl:DataRange vs rdfs:Datatype) as per http://lists.w3.org/Archives/Public/public-owl-wg/2008Jan/0017.html (see also http://lists.w3.org/Archives/Public/public-owl-wg/2008Jan/0147.html and thread)


General Discussion (Punning)

Punning discussion beginning now. Note that this will not be leading to a resolution today, this is intended only to be a discussion. Please see http://lists.w3.org/Archives/Public/public-owl-wg/2008Jan/0231.html for a list of the 5 questions about punning that we will be referring to, during this discussion.

First we consider question 1: Consider the punning issue to be divided into two kinds of punning. The first kind adds instance punning against classes and properties. In some sense this is the most easily understood kind of punning and those for which there are obvious use cases. The second kind are the other punning pairs - class/property, objectproperty/ dataproperty. Is it worth considering these separately? Do we have any kind of consensus that one or both are desirable/useful?

Peter Patel-Schneider: owl 1.1 allows at least six-way punning
Ivan Herman: 0 :-)
Jeremy Carroll: 0 for splitting
Boris Motik: -0
Sandro Hawke: +0 don't know enough about how the discussion will go, to have an opinion
Doug Lenat: 0
Markus Krötzsch: +0
Rinke Hoekstra: 0
Deborah McGuinness: 0
Zhe Wu: 0

Doug Lenat: It seems that there are no clear opinions on whether to distinguish those 2 kinds of punning.

Turning now to question 2: Two cited cases for punning are Metamodeling and being able to have real properties on classes/properties. But what exactly do people consider Metamodeling, and does the punning proposal address these cases. As an example, it does not address the cases on Conrad's Metamodeling page because we don't plan to support modification of owl syntax.

Boris Motik: "services" are instances, take instances of people,... the value of the property is not a particular person but the class Person.

Alan Ruttenberg: is there an expectation that monkey species statements flow to monkeys?

...Monkeys eat bananas meaning that EACH instance (each individual monkey) does this, and Monkeys is itself an instance of Species(Type)

...there is a reasonable case for treating classes as instances and properties as instances

Uli Sattler: ...but this will be taken care of with annotation spaces/other extended annotation mechanisms

Markus Krötzsch: the use case that Boris mentioned is similar to my experience. City instances have the property population, e.g.

Uli Sattler: ...but this is "class as individual" punning
Zakim: jjc, you wanted to ask for clarification of boris's annotation use case

...(Markus continues:) You don't know the types of things you have in advance, at least not always.

Michael Smith: I reinforce the container use case for data/object

Ivan Herman: Dublin Core had to worry about this with e.g. different ways to identify a person

Markus Krötzsch: +1 to Boris: punnig "metamodelling" does not require complex logical consequences

Boris Motik: in these examples, people are just stating things, and using idiosyncratic code to reason with those assertions.

Zakim: alanr_, you wanted to ask about annotation properties versus data/object punning and to mention logical consequences

Alan Ruttenberg: people want to restrict domains and ranges on class properties

...punning lets us use real properties and subproperties this way.

...Can someone compare data and object property punning to the use of annotation properties (pro or con)?

Boris Motik: when it comes to annotation-spaces, they require this type of punning.

...given an annotation in the original ontology, you need punning because in the new ontology it might be one of two or more types.

Uli Sattler: I still don't understand Alan's question...

Alan Ruttenberg: what about the annotation properties in Owl 1.0 -- still okay? still there?

Uli Sattler: not really, because in OWL1.0 we cannot pose any restrictions on this!

...[Alan continues:] in what sense is that not enough, why do we need to use punning for that now, suddenly?

Markus Krötzsch: +1 to uli: annotation properties cannot be used with enough OWL features

Jeremy Carroll: let's record these various use cases (on the wiki)

Evan Wallace: +1
Doug Lenat: +1
Boris Motik: +1
Markus Krötzsch: +1
Rinke Hoekstra: +1

See http://lists.w3.org/Archives/Public/public-owl-wg/2008Jan/0231.html

Ivan Herman: we already have http://www.w3.org/2007/OWL/wiki/PropertyPunning

ACTION: Markus to put his use case for punning onto a wiki page


ACTION: Boris to put his use case for punning onto a wiki page


ACTION: Alan to put his use case for punning onto a wiki page (for reasoning associated with punned properties, and the question about object data property punning vs annotation properties)


Rinke Hoekstra: very late +1 on uli's earlier remark on annotation properties and restrictions

Boris Motik: annotation properties (in OWL DL) not real properties

...they can have both indiv and data values

Evan Wallace: UML has association class, a natural way to talk about properties of relations.

...not its defintion, properties of the relation. Commonly used in UML.

ACTION: Evan action to describe UML association class on the wiki, w.r.t. punning discussions


Alan Ruttenberg: use cases where people want to do logical inference not just recording the assertions, please.

Markus Krötzsch: yes, I think

Michael Smith: describing another case, may be the same as Markus' essentially.

Turning now to the next question, number 3: From a technical point of view, how would dropping some or all of punning help? To what extent is the amount of new vocabulary dependent on our choice of punning? How does punning effect OWL Full?

Peter Patel-Schneider: no

Jeremy Carroll: ok

Peter Patel-Schneider: I repeat, the answer to question 3 is NO.

Jeremy Carroll: Issue 65, 69, and 68 are relevant: for each issue, the intro. of punning introduces new difficulties.

...so now we have to come up with three fixes for these three new problems.

...in order to allow punning.

...the owl DL and owl FULL gap is widened more than it would otherwise be, by allowing punning.

Alan Ruttenberg: q+ to try to separate increase in vocabulary motivations in to the two parts

Peter Patel-Schneider: disagree: if you're not limiting yourself to OWL DL, why should you care?

... Complicated mapping rules are worth it, if it makes the conversion of triples into ontology easier.

Boris Motik: why not allow a few more properties here and there, what is bad about that?

Peter Patel-Schneider: the mapping rules have been changed to make OWL DL parsing much easier, at a small expense - the driving factor is thus not punning, but parsing (as has been said before)

Alan Ruttenberg: tried to separate 2 issues. Incr. vocab makes the parsing of triples easier and deterministic.

...the addl vocab removes ambiguities and localizes information.

...This is a nice-to-have but not a need-to-have feature.

...But allowing obj/data polymorphism makes it more of a requirement than an option.

Peter Patel-Schneider: you may need some fancy footwork, to avoid ambiguity.

Uli Sattler: ...desirable or understandable?

Jeremy Carroll: to answer Boris: larger vocabularies means more work and may actually drive off other potential OWL users.

Uli Sattler: Jeremy, but these users will use tools to write ontologies, so perhaps they won't need to bother

Boris Motik: punning doesn't necessitate more vocab actually.

Jonathan Rees: +1
Bernardo Cuenca Grau: Regrets, I need to leave early today, bye

...(Boris continues:) using typing to specify the type of partic properties.

...(Boris continues:) if there is no obj/data punning.

Jonathan Rees: here's what i heard (of course i'm a newcomer) that I liked: Why not allow punning between class/property/individual, but not between dataproperty/objectproperty ?
Alan Ruttenberg: +1

Peter Patel-Schneider: using rdf + a litle bit of owl means what, exactly? you're probably not in owl-dl any longer.

Rinke Hoekstra: just a thought, but if this dl-specific vocab is confusing to rdf/full users, couldn't we introduce a different namespace for dl vocab? ... ah, but that introduces yet other syntactic bloat
Suggestion (guest): document describing OWL for RDFers [Scribe assist by Ian Horrocks]

Moving on to question 4 of http://lists.w3.org/Archives/Public/public-owl-wg/2008Jan/0231.html Namely: From a communication/understandability/documentation point of view, how would our choices effect the communities that we want to use OWL. What is the extra documentation needed to explain punning? How much would eliminating or reducing punning help? What's the appropriate balance of cost/benefit?

Ivan Herman: and what about a fragment like dlp?
Peter Patel-Schneider: a user of RDFS++ should have a document written for them (but maybe not by the WG)
Uli Sattler: I repeat my guess that these users will use tools to write ontologies, so perhaps they won't need to bother

Ivan Herman: agree with Jeremy; I'm afraid of bloating the number of things a user needs to learn.

...most users use some editing tool; for them, learning more is a major issue.

Peter Patel-Schneider: q+ say that OWL DL already needed to know, and OWL Full users don't

Uli Sattler: looking to the future, fewer and fewer people will be using standard editors to

...manually write OWL ontologies. Future tools will take care of more the bookkeeping details.

Peter Patel-Schneider: agree.

Uli Sattler: ...or have seen?
Ian Horrocks: +1
Ian Horrocks: Me too

Ivan Herman: there will be users who create complex ontologies and will need future sophis. tools.

Alan Ruttenberg: We are out of time. Deb will be the last to speak on the issue
Peter Patel-Schneider: only people who need to know are those writing OWL DL in RDF/XML

...but folksonomies staying at the DLP level is another more common situation.

Peter Patel-Schneider: ... directly in RDF/XML

...and those users will be around for many years, using EMACS eg and that's it.

Boris Motik: If they can learn to use vi, they can use the distinction between object and data properties :-)

...they won't be using Protege and similar tools that go way behond what they need.

Deborah McGuinness: stepping back a bit, to the general issue of adding more and more new constructs...

...maybe there is such a thing as too many.

Michael Smith: To the final question, it is necessarily the case that additional features complicate user documentation. Certainly this is the case with OWA and lack of UNA. Like those cases, the complication is a trade-off between documentation complexity and meeting use cases
Rinke Hoekstra: Note that we are again talking about vocab... but this is a different issue than punning itself?

...TO handle that, maybe select fragments ahead of time to help them focus on a useful subset or two.

Ian Horrocks: Look at SQL -- who knows all of the language, but many users seem to manage.

Doug Lenat: good point, Ian.

Uli Sattler: And even for documentation, you could hide/fold in some of these, I guess.

Issues

Decide whether to discuss these next N issues, or skip them. For a listing of the N issues, see Raised Issues in http://www.w3.org/2007/OWL/wiki/Teleconference.2008.01.23/Agenda

Jeremy Carroll: +1 to accept
Boris Motik: +1 to accept
Ivan Herman: +1
Doug Lenat: +1
Michael Smith: +1 to accept Issue 95
Peter Patel-Schneider: +1 to accept, and resolve quickly- its easy
Jeremy Carroll: (good catch)

No one minds discussing issue 95.

Rinke Hoekstra: +1 to accept
Alan Ruttenberg: +1
Evan Wallace: +1
Uli Sattler: +1

Issue 94 Problem with roundtripping when going from functional-style syntax into RDF and back

Boris Motik: +1 to accept
Alan Ruttenberg: +1
Markus Krötzsch: +1
Peter Patel-Schneider: -1
Evan Wallace: +1
Rinke Hoekstra: +1

Doug Lenat: -1 (because it's not completely clear that we want to support such roundtripping; we should explicitly discuss why or why not to provide such a guarantee.)

Ian Horrocks: +1
Jeremy Carroll: 0
Deborah McGuinness: +1
Uli Sattler: +1
Jeremy Carroll: q+
Ivan Herman: ack jjc
Ian Horrocks: q+
Rinke Hoekstra: this is a replacement of Issue 2, as far as I understood the minutes of last week
Peter Patel-Schneider: given the number of +1 votes, it seems that we need to accept the issue

Doug Lenat: Enough people want to discuss it, so yes, let's discuss it.

Ivan Herman: +1 to alanr
Peter Patel-Schneider: could we get the issue fixed up? or at least a def of OWL/RDF

Alan Ruttenberg: think also about whether and to what extent round-tripping is a requirement.

Michael Smith: Issue 2 is CLOSED already
Alan Ruttenberg: +1 to ian
Jeremy Carroll: ok
Boris Motik: AlLDisjointClasses
Jeremy Carroll: thank you
Alan Ruttenberg: Note that it was resolved for reasons other than roundtripping - n^2 -> n size for encoding

Issue 93 RFC 3066 - Tags for the Identification of Languages

Ian Horrocks: I'm afraid that I need to leave early this week, so TTFN.
Peter Patel-Schneider: there is the concern of duplicate "resolution" notes
Evan Wallace: +1
Doug Lenat: +1
Rinke Hoekstra: +1
Ivan Herman: +1
Zhe Wu: +1


Backward compatibility nits: see Issue 90, Issue 91 and Issue 92

Peter Patel-Schneider: the issue is built-in annotation properties (and related stuff) like deprecation

...Options related to deprecating classes, properties and datatypes

Peter Patel-Schneider: let's not preserve deprecation, though versioning is still required.

Uli Sattler: where do I find the semantics of deprecated classes?

Alan Ruttenberg: should we ignore them, treat them as annotations,...?

Peter Patel-Schneider: as for everything else, OWL S&AS
Boris Motik: Even in OWL 1.0 deprecation was ignored, so we can ignore it in OWL 1.1 as well.

Peter Patel-Schneider: depr. is special; it's wierd,... may be best strategy to just ignore it and see if something bad happens.

Uli Sattler: ...do we read this "who's screaming" with least or greatest fixpoint semantics?
Boris Motik: Just ignore them.

Jeremy Carroll: if we do deprecate deprecation, then we better ask other groups whether there is some unintended bad synergy with what they are doing.

Peter Patel-Schneider: I can put together a proposal
Jeremy Carroll: q+ to go back to Issue 93 (briefly)
Peter Patel-Schneider: no problem

ACTION: jeremy to edit references in syntax to address addison's bcp47 comment

ACTION: pfps (Peter Patel-Schneider) to write proposal to resolve 90 to drop deprecation and document in changes


ACTION: Patel-Schneider to write proposal to resolve 90 to drop deprecation and document in changes


Turning now to http://www.w3.org/2007/OWL/tracker/issues/91

Rinke Hoekstra: summarizing what it says on that link.

Alan Ruttenberg: I think we should keep ontology properties

Doug Lenat: Note that "ontology properties" are as follows: owl:imports, owl:priorVersion, owl:backwardCompatibleWith, and owl:incompatibleWith.

Peter Patel-Schneider: the state of owl:imports is: directive

Peter Patel-Schneider: i.e., something different than an annotation

Alan Ruttenberg: leave it as it is, not an ontol. property; make it subservient to versioning.

Uli Sattler: sounds like a good idea to me
Rinke Hoekstra: +1
Doug Lenat: +1
Evan Wallace: +1

Turning to Issue 92: The RDF to FS mapping does not provide a mapping for the owl:Ontology element to the Functional Style syntax

Peter Patel-Schneider: It is just a bug
Rinke Hoekstra: bug

PROPOSED: it's just a bug, so let's just fix it (i.e., treat it as nothing more than an editorial action).

Boris Motik: It is the inverse mapping; the mapping to RDF exists.
Boris Motik: I can fix that.
Peter Patel-Schneider: I thought I did at some point, but I can produce a proposal
Boris Motik: I'd consider this just editorial..

Doug Lenat: So the consensus is to treat it as an editorial issue (not something to discuss)

Any Other Business

Jeremy Carroll: regrets for next week
Alan Ruttenberg: adjourned