On Mon, April 2, 2012 18:09, John F Sowa wrote:
> Ali, (01)
> That point (copied below) is extremely misleading. Computational
> complexity is *always* a property of a problem. The same statement
> in full FOL could be undecidable for one kind of problem (e.g.,
> trying to prove it as a theorem), but it could be efficiently
> evaluated (polynomial time) for another problem (e.g., asking
> whether it is true in terms of a specific DB). (02)
> This is a simple fact about logic, which many people in the SW
> understand very well, but they keep parroting the party line that
> you have to reduce the expressive power of the language. That
> statement is *extremely* misleading. (03)
> Recommendation: Delete the following passage. (04)
I think the issue should be addressed. Instead of simply deleting
the passage, it should be replaced. (05)
3. Ontologies can be built to have both expressivity and scale. (06)
* Although an ontology may be highly expressive, uses of that ontology
need not calculate every statement that could be derived from the
rules in the ontology and the data in the local knowledge base. (07)
* Just because you CAN calculate something doesn’t mean you SHOULD
calculate it. Stick to information that is strictly useful to building
your
big data application. (08)
* Computationally expensive rules need not forward chain. (09)
* Backward chaining complex rules need not be computed in a knowledge
repository. Such calculations can be performed locally to answer
questions and the results can be stored back into the repository. (010)
* There can be a lot of value just getting the data federated and
semantically aligned. (38GD) (011)
> I suggest the following article for a more appropriate view:
>
> http://www.jfsowa.com/pubs/fflogic.com (012)
I think you meant: http://www.jfsowa.com/pubs/fflogic.pdf (013)
-- doug foxvog (014)
> By the way, Jim Hendler was the editor of the journal in which it was
> published, and he liked it very much. Pat Hayes also liked it.
>
> John
> ______________________________________________________________________
>
>
>> 3. *Many times people try to have both expressivity and scale. This
>> is very expensive* (38G5)
>>
><http://ontolog.cim3.net/cgi-bin/wiki.pl?OntologySummit2012_BigDataChallenge_Synthesis#nid38G5>
>>
>> * ***Don’t be seduced by expressivity* (38G6)
>>
><http://ontolog.cim3.net/cgi-bin/wiki.pl?OntologySummit2012_BigDataChallenge_Synthesis#nid38G6>
>>
>> * Just because you CAN say it doesn’t mean you SHOULD say it. Stick
>> to things that are strictly useful to building your big data
>> application. (38G7)
>>
><http://ontolog.cim3.net/cgi-bin/wiki.pl?OntologySummit2012_BigDataChallenge_Synthesis#nid38G7>
>>
>> * *Computationally expensive* (38G8)
>>
><http://ontolog.cim3.net/cgi-bin/wiki.pl?OntologySummit2012_BigDataChallenge_Synthesis#nid38G8>
>>
>> * Expressivity is not free. It must be paid for either with load
>> throughput or query latency, or both. (38G9)
>>
><http://ontolog.cim3.net/cgi-bin/wiki.pl?OntologySummit2012_BigDataChallenge_Synthesis#nid38G9>
>>
>> * *Not easily partitioned* (38GA)
>>
><http://ontolog.cim3.net/cgi-bin/wiki.pl?OntologySummit2012_BigDataChallenge_Synthesis#nid38GA>
>>
>> * Higher expressivity often involves more than one piece of
>> information from the abox – meaning you have to cross server
>> boundaries. With lower expressivity you can replicate the ontology
>> everywhere on the cluster and answer questions LOCALLY. (38GB)
>>
><http://ontolog.cim3.net/cgi-bin/wiki.pl?OntologySummit2012_BigDataChallenge_Synthesis#nid38GB>
>>
>> * *A little ontology goes a long way* (38GC)
>>
><http://ontolog.cim3.net/cgi-bin/wiki.pl?OntologySummit2012_BigDataChallenge_Synthesis#nid38GC>
>>
>> * There can be a lot of value just getting the data federated and
>> semantically aligned. (38GD)
>>
><http://ontolog.cim3.net/cgi-bin/wiki.pl?OntologySummit2012_BigDataChallenge_Synthesis#nid38GD> (015)
_________________________________________________________________
Msg Archives: http://ontolog.cim3.net/forum/ontology-summit/
Subscribe/Config: http://ontolog.cim3.net/mailman/listinfo/ontology-summit/
Unsubscribe: mailto:ontology-summit-leave@xxxxxxxxxxxxxxxx
Community Files: http://ontolog.cim3.net/file/work/OntologySummit2012/
Community Wiki: http://ontolog.cim3.net/cgi-bin/wiki.pl?OntologySummit2012
Community Portal: http://ontolog.cim3.net/wiki/ (016)
|