Re: SKOS, controlled vocab, and open world assumption

Hi Jeremy,

Two quick answers:

Of course provenance is the big issue here. An organisation might put 
more faith in vocabularies published as SKOS schemas by the European 
Publications Office [1], such as [2] than Jeremy's Ice cream vocabulary. 
The PO is working towards making all its URIs dereferenceable in very 
much a 'this is how it should be done' kind of way [3] but for now at 
least you can get directly at the RDF [4]. Applications may choose just 
to use a single source like that and not crawl the Web for every other 
term in that namespace.

The same thing applies in schemas - something I've raised before in this 
regard. If I declare dcterms:subject rdfs:range skos:Concept you can 
decide whether or not you care.

But... this is the open world scenario in all its glory of course. What 
might be interesting would be to get all the people faced with the 
dilemma "you know this linked data thing is really good and I can see 
all sorts of opportunities if only there were a way to close the world" 
into one room, say in Boston in September, and see what comes out [5].

Phil.


[1] http://open-data.europa.eu/open-data/data/
[2] http://open-data.europa.eu/open-data/data/dataset/0qMFlyqhv95veAyjqRNA
[3] http://philarcher.org/diary/2013/uripersistence/#cellar
[4] 
http://publications.europa.eu/mdr/resource/authority/role/skos/roles-skos.rdf
[5] http://www.w3.org/2012/12/rdf-val/cfp

On 05/04/2013 21:19, Jeremy J Carroll wrote:
>
> It is an explicit goal of SKOS to help with controlled vocabularies.
>
>
> These have a strange behavior with respect to open world assumption.
>
> If I define "Jeremy's Ice Cream Vocabulary" and decide that it only has one item "Raspberry" and Amanda  decides to use it in her application and Claudia is an end user of the App.
>
> We may expect that:
> - in the short term, Claudia, Amanda and Jeremy all have to put up with a very limited choice of gelato.
>
> When Claudia gets fed up with this, she may make a request to add Chocolate to the list, to Amanda, who may do so, but this doesn't change Jeremy's list; in fact, I may notice that Amanda has done this, and then decide to make the change myself; which in practice can lead to a failure mode in which Claudia is given a choice between Raspberry, Chocolate and Chocolate.
>
> So …. to abstract:
> Controlled vocabularies, by definition, have an authority who decide what's in and what's not in
> The user (typically the application designer) may well have local modifications, but rather than the open-world 'say anything about anything' they make a rather more restricted statement about their own world (we will use this additional term in this vocabulary)
>
> And vocabularies then have a change control problem ….
>
>
> Any thoughts? How are we meant to use SKOS to address these sorts of issues?
>
>
> Jeremy J Carroll
> Principal Architect
> Syapse, Inc.
>
>
>
>

-- 


Phil Archer
W3C eGovernment
http://www.w3.org/egov/

http://philarcher.org
+44 (0)7887 767755
@philarcher1

Received on Saturday, 6 April 2013 09:06:46 UTC