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Re: Guide: Version for F2F

From: Deborah McGuinness <dlm@ksl.stanford.edu>
Date: Sat, 05 Oct 2002 08:57:45 -0700
Message-ID: <3D9F0BF9.485BEC63@ksl.stanford.edu>
To: Leo Obrst <lobrst@mitre.org>
CC: Jeff Heflin <heflin@cse.lehigh.edu>, "Smith, Michael K" <michael.smith@eds.com>, webont <www-webont-wg@w3.org>



Leo Obrst wrote:

> Some comments below.
>
> Leo
>
> Jeff Heflin wrote:
>
> > Hi Mike,
> >
> > Since I will be unable to attend the F2F, here are my comments on the
> > Guide. In general, I think it is very good. I haven't had a chance to
> > read over other feedback you got, so if there are duplicates here, I
> > apologize.
> >
> > General Comments:
> > -------------------
> > - The sections should be numbered
> >
> > - You should use the common conventions for naming classes and
> > properties. People will emulate the examples in this guide, so if you
> > use upper case names for everything, that's what people will use
> > everywhere. The RDF convention is to use mixed case to separate words in
> > an identifier, and to begin class identifiers with capital letters and
> > property identifiers with lower case letters.
> >
> > - You need a section called "Using Ontologies to Describe Data" (perhaps
> > between Complex Property Axioms and Usage Examples). This section should
> > point out that once an ontology is developed, you will want to describe
> > data with it. It can mostly point back to the defining individuals and
> > properties of individuals sections, but should have additional material
> > on how ordinary documents import ontologies (this is of course still
> > TBD). If you put in a placeholder, I'd be happy to contribute the text
> > once imports is resolved.
> >
> > - Assuming we resolve the versioning issues, you'll also need a section
> > on "Versioning Ontologies." Once again, I'd be happy to contribute the
> > text once the WG agrees on a solution.
> >
> > Detailed comments:
> > ---------------------
> > - I think the short history is fine
> >
> > - The WG should think about whether it wants to advertise particular
> > companies (e.g., VerticalNet) in its official documents. I feel
> > uncomfortable with this. With the case in point, I think we can talk
> > about e-commerce in the abstract without losing much from the document
>
> I would exclude the specific reference to VerticalNet and just use B2B
> (business-to-business) e-commerce. Primarily because this is not now accurate.
> VerticalNet sold off its 59 verticals and is now a software provider, rather
> than directly a B2B company. I know, because I ran the ontology dept. there
> until the dot.com burst.
>

Giving evidence of the impact without explicitly mentioning the company can be
done with a citation to:
http://www.ksl.stanford.edu/people/dlm/papers/ontologyBuilderVerticalNet-abstract.html

it discusses the use of ontologies in e-commerce and the resulting requirements
for ontology environments.  this list of requirements was used to seed our
requirements document.

>
> >
> >
> > - In "The structure of ontologies", last sentence: define "entailed"
> >
> > - Once the imports and versioning issues have been resolved I'll suggest
> > some changes to the "Ontology Headers" section
> >
> > - In "Defining simple hierarchical named classes" (5th paragraph) you
> > say how rdf:resource and rdf:about can be used to refer to names. You
> > should explain the resource is used in properties and about is used with
> > class membership
> >
> > - Same section, next paragraph: "...permits the extension of the
> > imported definition of x without modifying the original resource" Do you
> > mean ontology instead of resource?
> >
> > - Same section, paragraph 8, "it is always possible to reference a
> > resource using its full URI..." You should say that when referencing
> > with "resource" or "about" to something from another namespace, you must
> > use the full URI. You can only use namespace abbreviations when the
> > class or property is an element name.
> >
> > - In "Defining individuals", 2nd example. type should be prefixed by
> > "rdf:" Can't have "VIN:" in the about or resource attribute values
> >
> > - Same section. You should mention what rdf:type means, thus explaining
> > why the two examples are equivalent.
> >
> > - In "Simple Properties - Defining Properties" Explain in words what a
> > domain and range are. Point out that because the Web is an open world,
> > these are not used to check data, but instead to infer things. For
> > example, if I have W as the subject of a "made-from-grape" predicate but
> > do not state that W is a Wine, this is not an error, but instead leads
> > to the inference that W must be a Wine. It is only an "error" if this
> > inference leads to a logical contradiction. Also mention that multiple
> > domains or ranges mean the domain or the range is the intersection of
> > all such classes.
> >
> > - Same section, 6th paragraph: Say what "subPropertyOf" means
> > generically.
> >
> > - Same section, 8th paragraph, "The first subClassOf defines an un-named
> > class...": I think you mean "second subClassOf". The first is just a
> > subclassof potable-liquid.
> >
> > - In "Property Characteristics and Restrictions": Shouldn't the axiom
> > for TransitiveProperty  be "P(x,y) and P(y,z) -> P(x,z)", not iff? Iff
> > would imply that for any value pair there was some intermediate value
> > that links them, implying that all such properties would have to have an
> > infinite set of values or at least be symmetric.
> >
> > - Same section: Give generic plain English definitions for each of
> > TransitiveProperty, SymmetricProperty, FunctionalProperty, and
> > InverseFunctionalProperty. Add syntax examples for each (except
> > inverseOf, which you already have.
> >
> > - In "Property Restrictions- allValuesFrom, someValuesFrom": give plain
> > English descriptions of the meanings of these terms
> >
> > - In "Cardinality", you say "We have already seen examples of
> > cardinality constraints." Is this right? I didn't see any previous
> > examples of cardinality constraints.
> >
> > - In "Set Operators", pargraph 4, "Classes can be identified as
> > closed...": I think this paragraph would be better stated by saying
> > something like "The intersectionOf operator takes the intersection of a
> > list of classes. Since the Semantic Web is assumed to be open, it is
> > important to explicitly state that this list is closed, i.e., all of its
> > members are listed. The rdf:parseType="collection" attribute is an RDF
> > trick for stating that the content of an element is a closed list of RDF
> > resources. In this case, a list of classes."
> >
> > - Same section, last example about FRUIT with two subclasses: We should
> > be clear that this does not have the same meaning as intersectionOf, it
> > says that Fruit is a subclassOf the intersection of SweetFruit and
> > NonSweetFruit (i.e., it might be smaller than the intersection). Unlike,
> > the intersectionOf operator, there might be some instances in this
> > intersection which are not Fruit. I also think this example should be
> > moved immediately after we discuss intersectionOf, instead of after
> > Union.
> >
> > - In "Disjoint Classes", last example: You ask if it is permitted. I
> > don't think so. First of all, having oneOf as a subelement to
> > disjointWith violates RDF striping rules (a class should go here). Now
> > if you wrap the oneOf in <Class>  and </Class> tags, it should be okay
> > as far as RDF is concerned but I don't think it will have the meaning
> > you intended. First of all, oneOf takes a list of instances as its
> > arguments, but you are providing classes. Whether or not this is legal
> > depends on the resolution of one of our outstanding contentious issues
> > (classes as instances). However, let's assume it is resolved in favor of
> > classes as instances. Then I would think it means that the classes MEAT,
> > FOWL, etc. cannot be members of EDIBLE-THING, but does not say anything
> > about their instances. That is, if Beef was a type of Meat then it could
> > also be a type of Pasta without contradicting your definition, but MEAT
> > could not be a type of Pasta.
> >
> > - In "Complex Property Axioms": You say that if you combined the two
> > restrictions it would "imply that all burgundies are dry" but the first
> > restriction already does this alone (i.e, every burgundy must have a
> > "Dry" value for SUGAR). It seems that the second restriction only says
> > that they can't have any other values as well.
> >
> > - In "Usage Examples" I have the same uneasiness about referencing
> > particular wine portals in a W3C spec. Is it really necessary?

people had asked for concrete examples thus the references.
i am not aware of anyone in the group who has any affiliations to the ones cited.
in particular, they were chosen because they came up as top hits on google
searches.
i think we need some examples.

> >
> > - I'm not sure if the "Wine Agent" example adds a whole lot of value to
> > the document.

this was in response to requests for how this can work today on the web.
if someone prefers/likes another slant, just let us know.


> >
> > - In "Appendix B": I think the syntax for saying hasSubArea is a
> > transitive property should be:
> >
> > <owl:ObjectProperty rdf:ID="hasSubArea">
> >    <rdf:type resource="http://www.w3.org/??/owl#TransitiveProperty">
> > </owl:ObjectProperty>
> >
> > Jeff
> >
> > "Smith, Michael K" wrote:
> > >
> > > I am not sure how 2 guides got in there.  A slip of the mouse.
> > > Here is what should have been included:
> > >
> > >  <<Guide.html>>  <<wines.owl>>
> > > - Mike
> > >
> > >   ------------------------------------------------------------------------
> > >                  Name: Guide.html
> > >    Guide.html    Type: Hypertext Markup Language (text/html)
> > >              Encoding: quoted-printable
> > >
> > >                        Name: wines.owl
> > >    wines.owl           Type: unspecified type (application/octet-stream)
> > >                    Encoding: quoted-printable
> > >             Download Status: Not downloaded with message
>
> --
> _____________________________________________
> Dr. Leo Obrst  The MITRE Corporation
> mailto:lobrst@mitre.org Intelligent Information Management/Exploitation
> Voice: 703-883-6770 7515 Colshire Drive, M/S W640
> Fax: 703-883-1379       McLean, VA 22102-7508, USA

--
 Deborah L. McGuinness
 Knowledge Systems Laboratory
 Gates Computer Science Building, 2A Room 241
 Stanford University, Stanford, CA 94305-9020
 email: dlm@ksl.stanford.edu
 URL: http://ksl.stanford.edu/people/dlm
 (voice) 650 723 9770    (stanford fax) 650 725 5850   (computer fax)  801 705
0941
Received on Saturday, 5 October 2002 11:54:50 GMT

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