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://ow
l-workshop.man.ac.uk/acceptedLong/ 
submission_26.pdf

On Apr 17, 2007, at 9:53 PM, samwaldgmx.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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> 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. 

In many cases we cannot do that.

> If at the statement level  
> you need to remodel so that you are clearly
communicating that you  
> are representing author statements.

In many cases we don't want to do that.
Representing everything as author statements (i.e.
statements about statements) would require wholly different
ontologies than those most of us are developing. Consistency
checking and inferencing over biological relations would
probably not be possible with such an ontology. There would
be no need to use a fancy OWL ontology and reasoner in this
scenario at all.

-Matthias




. 

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