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Re: draft responses for LC comment FH3/29

From: Bijan Parsia <bparsia@cs.man.ac.uk>
Date: Mon, 9 Mar 2009 13:09:19 +0000
Message-Id: <5AA91888-F774-4D1F-9942-94750ABCEEA8@cs.man.ac.uk>
To: W3C OWL Working Group <public-owl-wg@w3.org>
On 9 Mar 2009, at 12:54, Ivan Herman wrote:

> Bijan Parsia wrote:
>> On 9 Mar 2009, at 11:04, Ivan Herman wrote:
>>> First of all, don't shoot at the messenger...:-)
>> Are we?
> I am not sure:-)

Only water guns were used!
>>     There can be no useful AutoCompletion or validity checking for  
>> OWL
>> with Trix. You are stuck thinking at the triple level and any schema
>> that, e.g., tried to anticipate which triples had to have bnode  
>> subjects
>> or objects...well, I can't think of how to do it with out scheamtron.
> Neither do I. Or it would be horribly complicated (ie, error prone).

Even in schematron it'll be horribly complicated.

>>     The queries are brutal (even with sparql). For example,  
>> supposed you
>> wanted all the exact cardinality axioms. OWL/XML:
>>     /Ontology/element(*, Axiom)[./ObjectExactCardinality]
>> This will return that axiom. The sparql will be nasty (and  
>> require, for
>> example, a union in order to catch subclassof, equivalentclasses,  
>> etc.)
>> The XPath will be similarly nasty and hard to read.This makes  
>> anything
>> which uses XPath (XSLT, XQuery, Schematron) much harder to use (e.g.,
>> you'll just have to encapsulate the query in a function, and those
>> functions will be hard to debug, must be ported across Xquery and  
>> XSLT,
>> are non-standard in Schematron, etc.)
> I am not sure SPARQL is relevant for this discussion,

I was just pointing out that if someone thought that the problem was  
that you were using XPath instead of a triple oriented query  
language...that's *not* the problem :)

> because Jan's
> issue is around the XML encoding and usage in an XML food chain.  
> But the
> example shows that, although things are manageable via some sort of an
> XML (eg TriX) encoding + XSLT/XQUERY + XPath (which is Jan's argument)
> the result ain't pretty (an understatement:-)

We have different notions of "manageable". "Possible" is probably  
true, but basically by implementing a translator into OWL/XML (often  
ad hoc and half done). And even there, you loose stuff in the tool  
chain (validity checking with standard tools, WSDL embedding, etc.).

If we are thinking about developers, it seems pretty clear that  
having *one* pain point (having to translate OWL/XML into RDF) which  
is already a solved problem is much better than having a bazillion  
pain points which have to be solved again and again.

> Which probably gives some sort of a sketch answer to Jan...

Indeed :)

Here's, imho, a key point: I can now sensibly author OWL ontologies  
in oXygen. I could before, but only with extreme pain to the point of  
it not being worth it. I've started to build lots of little tools  
using standard language (schematron is *great* for adding ad hoc  
style/lint rules).

I've finished my upgrade of the OWL/XML schema and will be posting it  
later today or tomorrow with more examples.

Received on Monday, 9 March 2009 13:05:42 UTC

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