Re: Demo SPARQL notes

This is a debugging problem, but not a deployment problem. If one's  
data is inconsistent one needs to fix it. Usually such  
inconsistencies are either errors in the data that need to be fixed,  
or indications that one needs to get clearer about what one wants to  
say. In this case you need to make a choice about whether you want to  
say something that we called in [1] the 'statement level' or the  
'domain level'. If at the domain level you need to put your neck on  
the line and say which experiment is right. If at the statement level  
you need to remodel so that you are clearly communicating that you  
are representing author statements.

-Alan

[1] section 2,3 of http://owl-workshop.man.ac.uk/acceptedLong/ 
submission_26.pdf

On Apr 17, 2007, at 9:53 PM, samwald@gmx.at wrote:

>
>
>> I think *if the ontology classifies reasonably at all*, then this
>> sort of query approach can achieve reasonable performance for this
>> rough application profile with a reasonable amount of engineering
>> effort in many cases.
>
> Oh, but this is quite an important
> We can expect that most of the ontologies that are based on 'real  
> data' are inconsistent, if not even highly inconsistent -- not  
> because of errors on the side of the ontology designers, but  
> because the represented information is contradictory. For example,  
> we have found some inconsistency in one of our SenseLab OWL  
> versions that was caused by the fact that the results of two  
> experiments that were entered into the knowledge base were  
> contradictory. Of course, this is a good example for the utility of  
> an OWL reasoner, because it pointed us to a (potentially  
> interesting or important) contradiction in the literature.
>
> However, such contradictions could lead a reasoning-based approach  
> to querying fail, or at least they can make them less performant,  
> as you said.
>
>
> cheers,
> Matthias Samwald
>
>
>
>
>
> .
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Received on Wednesday, 18 April 2007 02:07:28 UTC