Re: SKOS, controlled vocab, and open world assumption

Hi Jeremy,
I can see how you describe the problem using English words.
But in the SKOS world, these would be URIs (which is sort of the point).
So for the two chocolates to happen, the URIs would have to be different (of course).
Is that what you mean?
But that would not correspond to the story.
When you notice that Amanda has added Chocolate, you add "it" to yours - is this the same URI as Amanda used (which might actually be a URI in your SKOS world, if we are not in the Linked Data world, where she wouldn't do that because it doesn't resolve)?
So I don't see the failure mode happening, because the Chocolates should have the same URI.
Of course, if you simply decide to add Chocolate(your-uri) which is different from Amanda's Chocolate(her-uri), then Claudia will be offered two Chocolate's - unless someone does some clever work to work out that they are actually owl:sameAs, if in fact that turns out to be true, but that is exactly as it should be.
To make it clear, I think you would need to retell your story (or another one) using URIs for the types of gelato.

Of course vocabularies do have change control problems, but this story seems to me to be dealt with quite nicely by the standard infrastructure, enabling apps to engage with changing vocabularies well.
Best
Hugh

On 5 Apr 2013, at 21:19, Jeremy J Carroll <jjc@syapse.com>
 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.
> 
> 
> 
>

Received on Saturday, 6 April 2013 10:38:19 UTC