- From: Pat Hayes <phayes@ihmc.us>
- Date: Wed, 23 May 2007 08:53:31 -0700
- To: Marijke Keet <keet@inf.unibz.it>
- Cc: Chris Mungall <cjm@fruitfly.org>, Phillip Lord <phillip.lord@newcastle.ac.uk>, public-semweb-lifesci@w3.org
>><snip> >>>> >>>>The history of computing is the history of >>>>"design patterns" at one level that >>>>eventually get built into "higher level >>>>languages" at the next level of abstraction >>>>up. >>> >>>I think I have a less optimistic view of >>>progress in computer science. For example, >>>many of the paradigmatic GoF design patterns >>>are there to make up for deficiencies in the >>>OO languages that *succeeded* more expressive >>>and abstract functional languages. >> >>Amen to that. And we are living through an >>exactly similar transition in representational >>languages, where DLs are re-inventing axioms of >>classical logic. >it's not quite re-inventing, although it may be >that "new features added to a language" are >sometimes being sold as if they were novel. I think it is often re-inventing. Take the current fuss about a W3C rule language, and how to 'add' it to OWL. Both rules and OWL are easily defined subsets of full FOL, so this ought to be close to trivial. BUt this isn't how it is being treated, and it is turning out to be anything but trivial, and is widely stated to require new, original research. >As for the n-aries in DLs (which are indeed >trivial in CL), that is possible in DLs in >theory for over 10 years and in software with >iCOM for >7 years -- and do the automated >reasoning over it, unlike with several other >logics. > >I like more expressivity as well, but then, I'm >not implementing systems where I'd have to wait >'long' for query answers or see my computer hang >.... I agree, of course there is an expressivity/efficiency trade-off. And in many ways, DLs have identified an important 'sweet spot' between the extremes. But the main role of a Web logic is to be a semantically clear, coherent, interchange medium. An expressive logic with a sound semantics is the best choice for that; and the various (because there are more than one) tractable subsets of it can be treated by efficient reasoners. The problem with the current SWeb design is that a variety of 'simpler' (actually the less expressive languages are often syntactically more complex) languages is still a VARIETY, which wrecks information interchange. Pat Hayes >upon classifying 1 instance in an 50-concept >small ontology (with the latest pellet for owl >1.1). I did try to load in Protégé and SWOOP the >FMA-lite, which is a 43MB OWL file. It failed. >Reasoning over sections of the FMA that take >into account only some constructors is possible >[1], which brings us back to your earlier >comment that "people have argued against more >expressive languages, in fact have argued with >great force and vehemence,": if we have to chop >up large ontologies anyway in order to be able >to reason over them, we might as well do that in >a structured manner with some simpler languages >and (semi-)automated conversions for "dumbing >down" a large and/or rich ontology to some >slimmed version that is computationally >tractable; that is, taking best of 'both worlds' >with expressivity where desired/needed and >performance where needed/desired. > >[1] Zhang S, Bodenreider O, Golbreich C. >Experience in reasoning with the Foundational >Model of Anatomy in OWL-DL. In:Pacific Symposium >on Biocomputing 2006, Altman RB, Dunker AK, >Hunter L, Murray TA, Klein TE, (Eds.). World >Scientific, 2006, 200-211. >http://helix-web.stanford.edu/psb06/zhang_s.pdf > >regards, >marijke > >C. Maria Keet >KRDB Research Centre >Faculty of Computer Science >Free University of Bozen-Bolzano >Piazza Domenicani 3 >39100 Bozen-Bolzano >Italy >tel: +39 04710 16128 >fax: +39 04710 16009 >email: keet@inf.unibz.it <mailto:keet@inf.unibz.it> >web: http://www.inf.unibz.it/krdb/ >home: http://www.meteck.org <http://www.meteck.org/> -- --------------------------------------------------------------------- IHMC (850)434 8903 or (650)494 3973 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32502 (850)291 0667 cell phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes
Received on Wednesday, 23 May 2007 15:53:51 UTC