W3C home > Mailing lists > Public > public-owl-wg@w3.org > April 2009

Re: Action-322 Review of New features and rationale.

From: Christine Golbreich <cgolbrei@gmail.com>
Date: Tue, 7 Apr 2009 09:55:05 +0200
Message-ID: <b0ed1d660904070055o47197a6uefc0fe58c97d844c@mail.gmail.com>
To: Alan Ruttenberg <alanruttenberg@gmail.com>
Cc: W3C OWL Working Group <public-owl-wg@w3.org>
Thank you for your review!

NF&R  has been strongly slimmed down. Sections 1 Introduction, 2
Features & Rationale, 4 Minor features, have been highly reduced and
compacted (thanks to Peter). This should solve your "overriding
concern", I hope.

Note that section 5.2 Backward Compatibility has been updated to deal
with backward compatibility and relationship with OWL 1

There are so many diff that I cannot list all, please  refer at  [1]

See details in line

[1] http://www.w3.org/2007/OWL/wiki/New_Features_and_Rationale


2009/4/1 Alan Ruttenberg <alanruttenberg@gmail.com>:
> Review of New Features and Rationale.
> On the positive side, I'd like to pass on a compliment given at a talk
> I recently gave on OWL, saying that the NF&R was quite helpful.
> In reviewing the document, the overriding concern I have in reading it is the
> length. I would like to see it compacted. In my review I give some
> examples. Detailed review is until section and is adequate to
> illustrate
> the general issues and potential solutions. I will continue a detailed review
> and send further comments.
> Generally
>  On review I don't see the need for the boxed syntax
>  description. The examples serve to demonstrate enough of the syntax,
>  and typographic emphasis could give an extra indication of which part
>  of the example is demonstrating the feature.

thank you for finally joining the general agreement on the syntax descriptions

>  In the examples, the subject heading, e.g.  the word "HCLS" below
>  "example", don't seem necessary and unnecessarily emphasize the noted
>  bias towards examples from this area. Note: I prefere the expanded "Health Care
>  and Life Sciences" instead of HCLS, in positions such as this, should
>  these be retained.

I retained the tags because it was a group request. Besides it would
not ne understandable why we have multôiple examples at some places.
Finally it seems useful for users.

>  RDF examples need a leading ":" at least, as they need to be
>  namespace qualified. The first example "BrainHemisphere" would be
>  ":BrainHemisphere".
>  There is the need for a careful proofread for grammar. I have given
>  examples where I have seen them.
>  While I support the idea of having RDF syntax examples as well, I
>  would like them to be implemented in the same way as in the other
>  documents, if kept.

I agree. This might be done later, when a uniform way is agreed by the
group for all documents

>  Mathematic expressions are used to explain some features, but not
>  others. I suggest we don't use them anywhere.


> Section 2.1
>  In the boxed examples, link UC#2. This also removes the need to list
>  them as a separate line after the box.
> Wording (appears for each of the two cases)
>  "Implementations, however, may prefer to take special notices of
>  DisjointClasses for more efficient processing"
> ->
>  "Implementations, however, may prefer to serialize using
>  DisjointClasses so as to minimize file size and parsing time."

Done, wording changed.

> "2.1.1 F1: DisjointUnion" use of the addition "F1" for cross
> referencing doesn't seem necessary. Why not just cite the sections
> directly?

abbreviations "F1" are used at many places to refer to the features
(e.g. see the Appendix) hence cannot be removed

> Section 2.1.2
> I would remove all or most of this note. If we keep anything, just
> "The FMA exhibits a huge number of such classes [FMA C in
> Appendix]"

> "Note: The FMA exhibits a huge number of such classes [FMA C in
> Appendix]: 3736 classes of template Left X vs Right X (e.g. Left lung
> vs Right lung) 13989 classes of template X left Y vs X right Y
> (e.g. Skin of right breast vs Skin of left breast) 25 classes with
> template Male X vs Female X (e.g. Male breast vs Female breast) 75
> classes X male Y vs X female Y (e.g. Right side of male chest vs Right
> side of female chest)"

Done, it has been compacted

> If kept, it would be outside the example box.
> The two examples are virtually the same. Drop one. I like the comment
> on the second example better: "Nothing can be both a Leftlung and a RightLung"

the other one is to show the use for *multiple* disjoontness

> Section 2.1.3
> "While OWL 1 provides means to assert values of a property for an
> individual, asserting that a property has not some values is
> impossible. This requires the ability to assert facts about an
> individual stating property values that it does not have"
> If it were impossible in OWL 1 it wouldn't be syntactic sugar. In fact
> it is possible but the alternative expression was deemed to be
> cumbersome and raise the overall difficulty of reasoning because of
> the use of nominals. It's probably worth writing one version of the
> OWL 1 way.


> You also say: "It's possible to take an ontology that is OWL 1 except
> for NegativePropertyAssertion and preprocess it into an equivalent OWL
> 1 ontology without it."
> I think it would be better to have the Theory and Implementation once
> for the whole section to reduce size, since it applies to all the
> cases of syntactic sugar.


> s/Implementaion/Implementation/
> Section 2.2.1
> Drop:  "For example, it might be appropriate to state that the
> skos:broader relationship is only locally reflexive or, alternatively,
> locally irreflexive w.r.t. skos:Concept (see also F6). "
> It's said in F6 anyways and confusing without the larger explanation.
> "Note: Global reflexivity may be used for local reflexivity in
> profiles which do not have local reflexivity (e.g., OWL 2 QL)."
> I don't understand this - global doesn't mean the same thing. Drop.
> Theory and implementation.
> "The description logic underlying OWL-DL is SHOIN. OWL 2 is based on a
> more expressive description logic: SROIQ [SROIQ]. SROIQ extension of
> SHOIN was designed to provide all possible useful additions to OWL-DL
> that were requested by users, while not affecting its decidability and
> practicability."
> This is something that is globally relevant. Include in the
> introduction, but not here, I think.


> The next seems unnecessary, or part of the introduction at best.
> "SROIQ logic extends SHOIN with reflexive, asymmetric, and irreflexive
> roles, disjoint roles, a universal role, and constructs ∃ R.Self. It
> also allows qualified number restrictions and negated role assertions
> in Aboxes. Additionaly, SROIQ offers complex role inclusion axioms of
> the form R ◦ S < R or S ◦ R < R to express propagation of one property
> along another one, which have proven to be very useful in particular
> for biomedical ontologies (see F8: Property chain inclusion)."
> Maybe keep this. Interested in feedback from others. But I'd lean towards
> dropping it.


> "Local reflexivity is already supported by existing tools, e.g.,
> FACT++. According to developers, local reflexivity was relatively easy
> to implement [TOOLS] – for any individual x that must have a
> relationship along a reflexive property, an appropriately labelled
> edge <x, x> has been added to the model."
> Section
> A good example of where dropping the syntax boxes and the domain
> headers would make this a more easily readable section.
> Drop "The following examples are some examples of Object Property
> Cardinality Restrictions from Use Cases among many in HCLS."
> "Class of objects having at least 5 direct part" s/part/parts/
> "Class of objects having atmost 5 Door" ->
> "Class of objects having at most 5 doors"
> "Class of objects having exactly 2 RearDoor"->
> "Class of objects having exactly 2 rear doors"
> 2.2.2
> Shorten:
> "As already said above, qualified cardinality restrictions are present
> in the SROIQ description logic underlying OWL 2 since they were
> required in various applications e.g.; [Medical Req] [Little Web] and
> did not pose theoretical or practical problems to be added [SHOIQ]. It
> has been known from a long time that resulting logic is decidable and
> QCR was already supported by DAML+OIL, the predecessor of OWL 1. QCRs
> do not pose an implementation problem either. It has been successfully
> implemented both in earlier editor, e.g.; OilED, and reasoner, e.g.,
> FACT++, that already processed ontology with QCRs, before OWL 1
> recommendation. Current versions of tools under development for OWL 2,
> e.g.; Protégé 4, FACT++, PELLET, RACER, KAON2 also deals with QCRs
> "It has been known for some time that OWL extended by qualified
> cardinality restrictions is decidable and  they were already supported by
> DAML+OIL, the predecessor of OWL 1[cite]."


> 2.2.3
> I suggest we remove this, as we don't support the antisymmetric
> properties needed for mereology, and in any case you can't use these
> property types with the transitive (i.e. composite) property part_of.
> "For example, in mereology, the partOf relation is defined to be
> transitive (if x is a part of y and y is a part of z, then x is a part
> of z), reflexive (every object is a part of itself), and antisymmetric
> (if an object has a part which in turn has part itself, then they are
> the same). Many applications, particularly those where it is necessary
> to describe complex structures, such as life science applications or
> more generally for systems engineering, require extensive use of
> part-whole relations, axiomatized according to these principles"
> Also drop "Other relations encountered in ontology modeling require
> similar axiomatizations as well, possibly with different sets of
> characteristics (see, e.g., [OBO] [RO])."

there is now a note is at the end motivating all the features (this
needs to remain because we refered to it in LC reponses)

> "Another interesting example" -> "An interesting example"


> "SKOS specification" -> "The SKOS specification"
> Rewriting a bit: "The SKOS specification [SKOS] makes no committment
> to the reflexivity or irreflexivity of the skos:broader
> relationship. The specification mentions that skos:broader should
> be considered reflexive "for a direct translation of an inferred OWL
> subclass hierarchy", but that irreflexive would be "more appropriate for
> most thesauri or classification schemes". With the addition of reflexivity and
> irreflexivity, OWL 2 allows one to express either of these choices.
> Self restrictions are even more fine grained, by allowing one to state
> that skos:broader should only be locally reflexive or irreflexive
> w.r.t. skos:Concept."


> Move to example box:
> One can make skos:broader locally irreflexive w.r.t. skos:Concept via an axiom
> SubClassOf(skos:Concept ComplementOf(ObjectHasSelf(skos:broader)))
> i.e. if x is a skos:Concept, then NOT( x skos:broader x ).

sentence removed

> Section
> I don't think that we need the mathematical expression. We don't do
> that uniformly.
> Comment says: "Everybody has the same blood group as himself" Should
> say "Every thing has the same blood group as itself". If you want to
> make it about people then it needs to be locally reflexive.


> I believe the example violates the global constraints.
> AsymmetricObjectProperty( proper_part_of )
> As propert_part_of is transitive.

and so ? we may give example that violate global constraints

> Theory and Implementation
> Include only "see F4 Theory and Implementation above Impementation was
> similar to the approach taken to support local reflexivity."

Received on Tuesday, 7 April 2009 07:55:41 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 7 April 2009 07:55:42 GMT