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Re: ISSUE-164 draft response

From: Alistair Miles <alistair.miles@zoo.ox.ac.uk>
Date: Thu, 16 Oct 2008 17:11:40 +0100
To: Antoine Isaac <aisaac@few.vu.nl>
Cc: SWD WG <public-swd-wg@w3.org>, Sean Bechhofer <sean.bechhofer@manchester.ac.uk>
Message-ID: <20081016161140.GC10428@skiathos>

On Thu, Oct 16, 2008 at 12:29:47PM +0200, Antoine Isaac wrote:
> Hi Alistair, Sean
>
> OK, I'll do that.
> Note that I think I will also add something in the Primer to (partially)  
> answer Dou'g comments on ownership. I'd propose this:
>
>> Finally, about your request for saying "something on how KOS  
>> developers might publish a vocabulary in SKOS, while asserting some  
>> practical form of ownership". I it is about the possibility to  
>> represent the provenance of statements that "compose" a KOS (e.g. the  
>> skos:inScheme statements), we unfortunately cannot propose an easy way  
>> for doing this for the moment. The resolution SKOS ISSUE-36 [3] gives  
>> hints about how this has been left to future implementations, e.g.  
>> using RDF named graphs. The Primer also touches the issue in section  
>> 3.1 (in "Note—owl:imports and re-using KOSs") [4]. We could however be  
>> more explicit, and propose to replace
>> [
>> If an application is concerned with provenance information, additional  
>> steps may be required in order to maintain the provenance of the  
>> imported triples. Such functionality is however currently outside the  
>> scope of SKOS.
>> ]
>> by
>> [
>> If an application is concerned with practical provenance or ownership  
>> information, additional steps may be required in order to maintain the  
>> provenance of the imported triples, using for instance RDF named  
>> graphs. Such functionality is however currently outside the scope of 
>> SKOS.
>> ]

Looks good.

You might also say something like "...additional steps may be required
to maintain the provenance or assert the authority of imported
triples..."?

I'm a bit out of my depth here tho, I'm not provenance or authority
expert.

Cheers,

Alistair.

>
> Not a big change, but at least the word "ownership" would appear in the  
> Primer, and a first hint at a solution would be mentioned.
>
> There is however a problem: when we decided on closing ISSUE-36, we had  
> a piece of text that was refering to named graphs explicitly, and also  
> SPARQL patterns. But now this does not appear any more in the Reference.  
> Maybe I've missed a further resolution on that point, but I guess that  
> closing an issue with a resolution that is not completely implemented in  
> our docs is not really good, is it?
>
> Antoine
>
>
>> Hi Antoine,
>>
>> On Tue, Oct 14, 2008 at 02:57:53PM +0200, Antoine Isaac wrote:
>>   
>>> Hi Alistair,
>>>
>>> OK, I had not really thought about the possibility to postpone things 
>>>  for next future...
>>> I think your mail would be actually a good answer to (this part of)   
>>> Doug's comments.
>>>
>>> If I sum up, the answer to Doug's original mail would be for the moment:
>>> - the points that you approved in [1]
>>> - something that I'd derive from your mail below
>>>
>>> Does this sound OK?
>>>     
>>
>> That sounds great.
>>
>> Cheers,
>>
>> Alistair.
>>
>>   
>>> Antoine
>>>
>>> [1] http://lists.w3.org/Archives/Public/public-swd-wg/2008Oct/0135.html
>>>
>>>     
>>>> Hi Antoine,
>>>>
>>>> I'd rather not say anything at all. If we do, I think we're
>>>> overstretching. I suggest we niether encourage nor discourage this
>>>> practice. We really have no experience here, so better to say nothing
>>>> and let the community define best practice in response to
>>>> implementation experience.
>>>>
>>>> If Doug believes this practice is potentially harmful, I encourage him
>>>> to publish a brief best practice note and inform the SKOS community
>>>> via the mailing list. I'd also be more than happy to set up a "SKOS
>>>> community best practices" wiki page to collect links to such
>>>> statements.
>>>>
>>>> Practices for KOS linking would also be the subject of a very
>>>> interesting research paper :)
>>>>
>>>> Cheers,
>>>>
>>>> Alistair.
>>>>
>>>> On Mon, Oct 13, 2008 at 08:20:09AM +0200, Antoine Isaac wrote:
>>>>         
>>>>> Hi Alistair,
>>>>>
>>>>> Thanks for your comments!
>>>>> About the part of my answer you find debatable:
>>>>>
>>>>>             
>>>>>>> Regarding your last comment on the potential problems raised 
>>>>>>> by   extension and inclusion of concepts in different 
>>>>>>> schemes, I'd propose  the following note:
>>>>>>> [
>>>>>>> Note -- messing with existing KOSs. RDF provenance mechanisms 
>>>>>>> may be  used to track additions to a KOS that are not done by 
>>>>>>> its original   designers. However, such functionality is 
>>>>>>> currently outside the scope of  SKOS. Accordingly, this 
>>>>>>> document encourages publishers of new SKOS  concepts not to 
>>>>>>> include them via skos:inScheme statements into existing  KOSs 
>>>>>>> that they do not not "own". In the above example, one should  
>>>>>>> therefore not assert that ex2:abyssinian belongs to   
>>>>>>> ex1:referenceAnimalScheme.
>>>>>>> ]
>>>>>>>                         
>>>>>> I'm not sure about this. Just because SKOS does not deal with RDF
>>>>>> provenance, does not mean there aren't good solutions elsewhere. I
>>>>>> suggest not to include the last two sentences.
>>>>>>
>>>>>>                   
>>>>>>> Notice that this last note also adresses your request for 
>>>>>>> saying   "something on how KOS developers might publish a 
>>>>>>> vocabulary in SKOS,  while asserting some practical form of 
>>>>>>> ownership". For the moment, we  unfortunately cannot propose 
>>>>>>> an easy way for doing this.
>>>>>>>                         
>>>>>> ...but we encourage the community of practice to develop
>>>>>> solutions. SKOS can only go so far, the rest is up to the community.
>>>>>>                   
>>>>> I guess you're right, that people could one day use cool 
>>>>> provenance   mechanisms. However, Doug's comment was making much 
>>>>> sense, and even with  appropriate provenance mechanisms I do not 
>>>>> think it is very good  practice to include one's own concepts in 
>>>>> someone else's concept scheme,  when this someone else is likely 
>>>>> not to have anticipated such an  addition. Otherwise I'd feel it 
>>>>> would be encouraging some cuckoo  behaviour ;-)
>>>>>
>>>>> As a compromise we could soften the end of the note:
>>>>> [
>>>>> Note -- messing with existing KOSs. RDF provenance mechanisms may 
>>>>> be  used to track additions to a KOS that are not done by its 
>>>>> original   designers. However, such functionality is currently 
>>>>> outside the scope of  SKOS. Generally, this document thus 
>>>>> encourages publishers of new SKOS  concepts not to include them 
>>>>> via skos:inScheme statements into existing  KOSs that they do not 
>>>>> not "own", unless they do so using mechanisms that  allow 
>>>>> distinguishing clearly the information they publish. In the above 
>>>>>  example, one should therefore not assert that ex2:abyssinian 
>>>>> belongs to  ex1:referenceAnimalScheme using a bare,  
>>>>> provenance-neutral skos:inScheme  triple.
>>>>> ]
>>>>>
>>>>> Would that be ok?
>>>>>
>>>>> Cheers,
>>>>>
>>>>> Antoine
>>>>>
>>>>>             
>>>>>> Cheers,
>>>>>>
>>>>>> Alistair.
>>>>>>
>>>>>>
>>>>>>                   
>>>>>>> I hope these modifications seem appropriate to you. Please do 
>>>>>>> not   hesitate to send further comments, your experience is 
>>>>>>> really  precious!
>>>>>>>
>>>>>>> Best regards,
>>>>>>>
>>>>>>> Antoine
>>>>>>>
>>>>>>> [1] http://lists.w3.org/Archives/Public/public-swd-wg/2008Oct/0062.html
>>>>>>> [2] http://www.w3.org/TR/skos-ucr/#Accepted
>>>>>>>
>>>>>>>                         
>>>>>>>> ISSUE-164: Extension vs mapping (SKOS Primer)
>>>>>>>>
>>>>>>>> http://www.w3.org/2006/07/SWD/track/issues/164
>>>>>>>>
>>>>>>>> Raised by: Antoine Isaac
>>>>>>>> On product: SKOS
>>>>>>>>
>>>>>>>> Raised by Doug Tudhope in [1]
>>>>>>>>
>>>>>>>> Open world discussion and extension vs mapping in 3.1 and 3.2
>>>>>>>>
>>>>>>>> I’m a little concerned about the relative emphasis apparently given to extension
>>>>>>>> vs mapping. The primer might be read as suggesting that the default way of
>>>>>>>> connecting two KOS is via extension or direct linking, which I think would be
>>>>>>>> inappropriate. While there are good cases for (third party) extending a KOS (eg
>>>>>>>> by including local extensions), the wording in the intro to section 3 is perhaps
>>>>>>>> a little enthusiastic and might run the risk of not sufficiently recognizing the
>>>>>>>> potential problems of linking two different KOS. LIS experience has recognised
>>>>>>>> that any major KOS represents a particular world view and that joining two
>>>>>>>> different KOS in an effective manner is not necessarily straight forward. Hence
>>>>>>>> the emphasis on distinct mapping relationships.
>>>>>>>>
>>>>>>>> Perhaps the editorial team could consider the appropriate order of the linking
>>>>>>>> and mapping sections, whether more discussion on the rationale for mapping could
>>>>>>>> be included, and whether some more guidance might be given on when to link and
>>>>>>>> when to map.
>>>>>>>>
>>>>>>>> The linking example in section 3.1 brings up a currently somewhat problematic issue.
>>>>>>>>   A new concept scheme can re-use existing concepts using 
>>>>>>>> the   skos:inScheme
>>>>>>>> property. Consider the example below, where a reference concept scheme for
>>>>>>>> animals defines a concept for "cats":
>>>>>>>>   
>>>>>>>>
>>>>>>>> However there is nothing to prevent a new developer attaching their own new
>>>>>>>> concept to someone else's existing SKOS scheme and thus changing the scheme (if
>>>>>>>> the links are followed). It would be bad practice but as far as I understand is
>>>>>>>> possible. (A slight modification of the example in 3.1 illustrates the point below.)
>>>>>>>>
>>>>>>>> I appreciate this is integral to the open world model and in the long run, it
>>>>>>>> might be addressed by mechanisms of assigning provenance to RDF (sets of)
>>>>>>>> statements, development of trusted vocabulary registries, caution when importing
>>>>>>>> a SKOS vocabulary, etc. In the near future, I believe that the majority of
>>>>>>>> applications will be effectively closed world, in that they will create an
>>>>>>>> in-house index or database based on selected resources from the Web (including
>>>>>>>> linked data publications). Perhaps the SKOS primer might also address more
>>>>>>>> immediate concerns of how a vocabulary provider might make their vocabulary
>>>>>>>> available. Is it possible to say something on how KOS developers might publish a
>>>>>>>> vocabulary in SKOS, while asserting some practical form of ownership?
>>>>>>>>
>>>>>>>> Apdx
>>>>>>>>
>>>>>>>> Eg A slight modification of the example in 3.1 if I understand it correctly
>>>>>>>> ============= alt example (undesirable?)
>>>>>>>> ex1:referenceAnimalScheme rdf:type skos:ConceptScheme;
>>>>>>>>    dc:title "Reference list of animals"@en.
>>>>>>>> ex1:cats rdf:type skos:Concept;
>>>>>>>>    skos:prefLabel "cats"@en;
>>>>>>>>    skos:inScheme ex1:referenceAnimalScheme.
>>>>>>>>
>>>>>>>> The creator of another concept scheme devoted to cat descriptions can freely
>>>>>>>> include the reference ex2:abyssinian concept in AN EXISTING scheme, and then
>>>>>>>> reference it as follows:
>>>>>>>>
>>>>>>>> ex2:catScheme rdf:type skos:ConceptScheme;
>>>>>>>>    dc:title "The Complete Cat Thesaurus"@en.
>>>>>>>>
>>>>>>>> ex1:cats skos:inScheme ex2:catScheme.
>>>>>>>>
>>>>>>>> ex2:abyssinian rdf:type skos:Concept;
>>>>>>>>    skos:prefLabel "Abyssinian Cats"@en;
>>>>>>>>    skos:broader ex1:cats;
>>>>>>>>    skos:inScheme ex1:referenceAnimalScheme.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>                                 
>>>>>>>                         
>>>>>>                   
>>>>>             
>>>>         
>>>     
>>
>>   
>

-- 
Alistair Miles
Senior Computing Officer
Image Bioinformatics Research Group
Department of Zoology
The Tinbergen Building
University of Oxford
South Parks Road
Oxford
OX1 3PS
United Kingdom
Web: http://purl.org/net/aliman
Email: alistair.miles@zoo.ox.ac.uk
Tel: +44 (0)1865 281993
Received on Thursday, 16 October 2008 16:12:19 GMT

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