Re: SV: SV: SV: FW: [plcs-dex] Unique constraints -> identification and versioning

[David Price <david.price@eurostep.com>]

Hi Mats, I agree good discussion... see below.

Question on the FMV model - Did you look at ISO 11179 which seems to have the 
same scope? For PLCS RD, as for anything else, it's very tempting to think 
noboby else shares our requirements (as my good friend Larry Johnson at OMG 
used to say, physicists stand on each others shoulders while software 
engineers stand on each others toes). However, for RD we were trying not to 
re-invent the wheel but use a widespread technology that was already 
implemented on the Web so we choose the Dublin Core. I agree processes around 
the development of the RD are not as well-defined as they should be.

Cheers,
David

On Wednesday 20 December 2006 08:42, mats.nilsson@fmv.se wrote:
> Hi,
>
> (See P.S. statement regarding the attachment and my approach to this
> discussion) (I've copied the section from David answer below on which I'd
> like to comment on)
>
> >  I understand the question now. From what I've seen on the Semantic Web,
> > the best practice is to use a (somewhat) human-interpretable name for the
> > identifiers of classes in an ontology (within the limitations of what you
> > can use in a URL or URI).  I agree that the use of rdfs:label is the
> > proper way to specify the "name" of the class for use in browsers and GUI
> > applications. However, I don't see any advantage in not following the
> > Semantic Web practices. I've never really understood why anyone would
> > want classes with ids like rd0049404 when they can have SerialNumber.
>
> 1. I'm not sure that the "Semantic Web best practice" is something we
> should pay to much attenention to, because imho PLCS Reference Data and
> Semantic Web ontologies are not that closely related, even though we use
> the same XML application (i.e. OWL) for the representation.

Actually, the Semantic Web folks have Taxonomy directly in their sights ... 
and so I do think their approaches are quite relevant. I do also hope that 
the PLCS RD is reusable by reasoning apps.

>
> 2. There will sooner or later be a case when homonyms appear in the same
> ontology. For now I have the two examples 'Tank' (container for liquid -or-
> combat vehicle) and 'Stone' (a unit of mesure -or- a primitive tool for
> emergency repairs). Both these examples are homoonyms likely to appear in
> the same domain (even though the 'Stone' example is a bit far-fetched...).
> In this case there still has to be a 'Stone(tool)'/'Stone(unit)' notation
> in order to separate them. A "meaninless" id string would bo more
> efficient.

Why is meaningless more efficient? The Ontology Engineer simply needs to pick 
one of the possible names and use it as part of the URI. What about the poor 
DEX implementor who can make no sense at all out of the classifications in an 
exchange file without an application to read it and present the labels found 
in the OWL ontology? I'd argue meaningful is more efficient. Same answer for 
question 3 and 4.

The reason for using English is that the normative text defining AP239 and the 
RD classes is in English. If it was standardized in French, I'd argue that 
language should be used for the URI. Compare:

An RD039405950 is a unique number that is one of a series assigned for 
identification which varies from its successor or predecessor by a fixed 
discrete integer value.

and

A SerialNumber is a unique number that is one of a series assigned for 
identification which varies from its successor or predecessor by a fixed 
discrete integer value.

and you'll see what I mean. BTW, the definition comes from Wikipedia.

>
> 3. You (David) did not comment on the real-world (...FMV...) fact that more
> than one word (synonyms) exists as "labels" for the same class. Which one
> should be used for the id? The use of the OWL "same_as" construct with
> separate classes (with identical definitions) is to me a more complicated
> way then using 'rdf:label' for the words and a "meaninless" id string for
> the class as a whole.
>
> 4. In the "interoperability" or "multilingual" oriented world there could
> also be a reason to keep the 'rdf:ID'='external_class.id' as a "meaninless"
> id string, in order to allow "labels" in different languages and not beeing
> forced to use an English word as the identifier... Why not adopt (what I
> think is) the eOTD approach. What they do and what we do are quite similar
> when it comes to "concept management" (where
> concept=id+label(s)+definition). Their "Core Model" (and perhaps the "FMV
> concept management information model"... (attached)) might be something to
> take a look at.
>
> I'm glad we got the discussion started! I hope more will join in...
> Reference Data is a key aspect to PLCS which in my opinion still is a bit
> too loosely defined.
>
> Regards,
>   Mats
>
> P.S.
>   The attached "FMV concept management information model" is still at a
> draft level (and has yet no descriptive text). Its purpose is to be the
> base for the definition of an XML based format for the representation of
> terminology used within FMV (and in the long run also for the Swedish armed
> forces). A project for addressing "concept management" will start at FMV in
> january with me as the projet leader.
>
> In order to be able to classify PLCS data correctly, the classifications
> should be based on a defined terminilogy. FMV doesn't have that today. In
> order for PLCS to work - this must be established! The aim of the project
> is first to create an infrastructure (data format, applications, processes,
> information/education and organisation), and then to launch the
> organisation and the work of creating a defined terminology. The
> infrastructure section of the project should be completed before summer! My
> ambition is, as far as it is possible, to use OWL in the same way as the
> OASIS PLCS TC specifies its use (something we'll soon have to agree on and
> do...) for our (FMV) terminology data format.
>
> This might explain some of my opinions expressed above and earlier...
>
>
>
>
> -----Ursprungligt meddelande-----
> Från: David Price [mailto:david.price@eurostep.com]
> Skickat: den 19 december 2006 17:30
> Till: plcs-dex@lists.oasis-open.org
> Ämne: Re: SV: SV: FW: [plcs-dex] Unique constraints -> identification and
> versioning
>
> Hi Mats, See below for two replies. Cheers, David
>
> On Tuesday 19 December 2006 09:38, mats.nilsson@fmv.se wrote:
> > Hi David,
> >
> > This is one of your examples of a "class.id URI";
> >
> > >> urn:iso:std:iso:ts:10303:-1017:ed-1:tech-taxonomy:Part
> >
> > If I understand you correctly, you suggests to include both the URI for
> > the RDL ("urn:iso:std:iso:ts:10303:-1017:ed-1:tech-taxonomy") as well as
> > the class identifier ("Part") in the 'external_class.id' (the 'id'
> > attribute in the 'external_class' entity).
> >
> > I thought (see the last of my three slides) 'external_class_library.id'
> > was going to be used for the URI of the RDL, and that the identifier
> > within the RDL (i.e. 'external_class.id') only should contain the actual
> > "classification" or "term" identifier, in your example "Part".
>
> I don't think that works because of the other issues I mentioned (i.e.
> there are multiple ontologies involved and one ontology has to be
> identified as the context ontology). The context ontology is the most
> organization-specific ontology that uses the more general and standard
> ontologies.
> External_class_library is really the only entity type in PLCS that makes
> sense for that requirement and so I think there should be one instance of
> it that all the External_class entity instances point to (actually I don't
> think it's a big problem if there are multiple instances of
> External_class_library as long as they all refer to the same URI. So, if
> you've followed and agreed with the logic of requiring a context ontology
> then I think it's clear that the External_class.id needs to be the full
> URI.
>
> For what it's worth, I think people have been assuming that
> "urn:oasis:plcs" was "the reference data library", when in fact in
> real-world usage that is unlikely to be the case. The RDL that is the
> context for an exchange is actually the ontology developed by the using
> organization with its extensions to the PLCS standard classes which is
> imported in read-only mode. Because of the flexibility enabled by the use
> of the OWL language, it's important to have that context ontology named in
> the exchange file. If you look at some of the OWL APIs you'll see that they
> often force you to supply an ontology when you'd think only a class is
> required as input. That's because the same class can have different
> subclasses *and* superclasses (not to mention properties) depending on how
> it is extended in using ontologies.
>
> > Please help me understand if I've got things wrong! If someone else has
> > an opinion, please help David help me...
> >
> >
> > Now over to your question David. In my not so organized world (I call it
> > FMV...) people use more than one term for the same concept
> > (concept=class). OWL has the 'rdfs:label' element, which makes it
> > possible to assign more than one term for each class. This is useful for
> > me because the guys who drive helocopters and those who drive boats often
> > have different terminology, and I can use this functionality to make them
> > understand each other and the data they send. There is also this need to
> > be "interoperable" within e.g. the EU Battle Groups or NATO joint
> > operations, and then we swedes meet people that uses the word "lubricate"
> > for what we call "smörja"...
> >
> > To accompish this I'd like to use a "meaningless" identifier for the
> > 'external_class.id' field, e.g. "rd000453" (or with versioning
> > "rd000453v1"), and then use the 'external_class.name' field for the
> > readable classification (i.e. one of the available 'rdfs:label's in the
> > RDL/OWL-file).
> >
> > This was what I meant by the question;
> >
> > >> David: How do you suggest the label used for
> > >> classification should be identified in case there are multiple labels
> > >> for the same class/RD?
> >
> > If I have both "lubricate" and "smörja" in the same class (that is a
> > subclass of 'activity'/'task') with some unique id, I need to specify
> > which one is used.
> >
> > Clearer? Or don't you see this scenario with synonyms and multiple
> > languages (used for the same class/concept)?
>
> I understand the question now. From what I've seen on the Semantic Web, the
> best practice is to use a (somewhat) human-interpretable name for the
> identifiers of classes in an ontology (within the limitations of what you
> can use in a URL or URI).  I agree that the use of rdfs:label is the proper
> way to specify the "name" of the class for use in browsers and GUI
> applications. However, I don't see any advantage in not following the
> Semantic Web practices. I've never really understood why anyone would want
> classes with ids like rd0049404 when they can have SerialNumber. The only
> rationale I've heard that made any sense to me was related to handling the
> uniqueness of ids but since we're engineering the reference data I don't
> think the cost in human understandability is outweighed by the small
> benefit of slightly easier uniqueness. That said, I also think that the
> PLCS RD should be broken up into sub-ontologies on a domain-by-domain basis
> for manageability, subsetting and to help with the overloading of terms.
>
> All that said, I'm not sure that the External_class.name is really useful
> for transfering rdfs:label values. I'm not sure of the business need for
> that for a start. If the External_class.id is the full URI then that's
> sufficient for an application to process. If for some reason the rdfs:label
> is needed then I think name_assignment is the only way to handle the fact
> that a class may have multiple rdfs:label values for different languages.
> However, it seems to me it's better to keep all the labels in the ontology
> itself rather than duplicating them in the exchange file.
>
> > Regards,
> >   Mats
> >
> >
> >
> > -----Ursprungligt meddelande-----
> > Från: David Price [mailto:david.price@eurostep.com]
> > Skickat: den 18 december 2006 18:05
> > Till: plcs-dex@lists.oasis-open.org
> > Ämne: Re: SV: FW: [plcs-dex] Unique constraints -> identification and
> > versioning
> >
> > Hi Mats, a few replies follow (although I'm confused by one question.
> >
> > On Monday 18 December 2006 07:51, mats.nilsson@fmv.se wrote:
> > > Questions below...
> > > Happy for opinions!
> > >
> > > Regards,
> > >   Mats
> > >
> > > >> David: Could you please give an example of what an (external)
> > > >> class.id URI could look like?
> >
> > It would be a URN or a URL depending on what organization defines it the
> > class and the approach they happen to have adopted. It would be the
> > compete URI for the class though it's technically only the identifier and
> > so may not be sufficient for location (e.g. if it's a URN then some other
> > means would have to be established for an application/user to find more
> > info about the class ... for example, an organization might have to buy
> > an ISO standard). Examples could be:
> >
> > urn:iso:std:iso:ts:10303:-1017:ed-1:tech-taxonomy:Part
> >
> > http://schema.omg.org/spec/UML/2.1/ParameterDirectionKind
> >
> > http://www.madeupdod.mil/ActivityOntology#Training
> >
> > > >> David: How do you suggest the label used for
> > > >> classification should be identified in case there are multiple
> > > >> labels for the same class/RD?
> >
> > I don't understand what "the label used for classification" means. Can
> > you rephrase the question or explain that phrase?
> >
> > Cheers,
> > David

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