- From: Pat Hayes <phayes@ai.uwf.edu>
- Date: Thu, 6 Dec 2001 10:41:34 -0600
- To: "Smith, Ned" <ned.smith@intel.com>
- Cc: www-webont-wg@w3.org
>-----BEGIN PGP SIGNED MESSAGE----- >Hash: SHA1 > >Pat, >I'm quite interested in seeing item 1) below realized. Scenario 3) in >the use cases I proposed is tied to proof carrying authorization. > >BTW: How would you classify the language you describe below? The >language is more expressive than a description logic, yet not exactly >a 1st order logic or type theory logic. Are you suggesting this is >the language WebOnt will define? I would like to see it move that way, yes. In fact (I hesitate to say this in case the Captain is listening) I would suggest something like a 'neat' syntax for FOL - perhaps a subset, eg a constructive or intuitionist subset(?) - with a distinguished typing syntax that is similar in power (though maybe not quite in form) to DAML+OIL, ie a genuine logical extension of DAML+OIL. The DAML+OIL-like subset would be the language for defining logical sorts in the full language, and there would of course be natural ways to translate them into logical form if anyone wanted to, but such a translation would abandon the proven utility of the class-based reasoning engines. (The emerging ISO-KIF standard might provide a basis; but it would need to be re-done in more Webbish way, related to XML and so on.) I am quite sure that eventually the SW is going to re-discover the utility of FOL, just as AI and KR and database technology eventually did, and I would like it to be sooner rather than later. > In what ways does DAML+OIL hit/miss >the objective? Well, DAML+OIL should obviously be included as a sublanguage, in such a way as to preserve its computational properties. (But I don't think we should try to *reduce* the WOL to DAML+OIL; that kind of reduction is likely to produce all kinds of semantic problems, in spite of its perceived advantages in avoiding the need to write parsers.) I think that as a basic ontology language, DAML+OIL is 'warped' by its being a class/property language rather than a conventional logical language. For things that are simple and natural to state as in class/property terms it is fine, but other kinds of propositions require one to introduce very artificial classes defined in terms of restrictions in order to state simple facts (and simple queries), and the resulting complexities of needing to learn to think in this odd way add further barriers to the already considerable difficulties of using DAML+OIL. It seems to me that there are some things that class reasoning does extremely well, but other things it is less well suited to, and that we should attempt to provide a language which allows it to be used naturally, but does not insist on its being used at all times. This is hardly a new opinion, of course: description logics emerged from the old idea of there being two kinds of representation, which used to be called the A-box and the T-box. I would like us to have both boxes again, is all. Pat Hayes >Thanks, >Ned > >Ned M. Smith >Intel Architecture Labs Phone: 503.264.2692 >2111 N.E. 25th Ave Fax: 503.264.6225 >Hillsoboro OR. 97124 mailto:ned.smith@intel.com > > >> -----Original Message----- >> From: Pat Hayes [mailto:phayes@ai.uwf.edu] >> Sent: Thursday, November 29, 2001 8:40 AM >> To: www-webont-wg@w3.org >> Subject: WEBONT "HOMEWORK" >> >> >> >> What I would like: >> > > 1. An ontology language which was expressive and 'natural' enough >> to encode most currently extant ontologies. That is considerably >> more expressive than a description logic, but it can have a >> description logic as a natural sublanguage (the part of the larger >> language that deals with type-class reasoning). The natural choice >> would be some variant of either an extended first-order logic such >> as ISO-KIF, or possibly a type theory-based logic like LF. Part of >> the development work would be to include a notion of >> proof-carrying authorization in the proof theory of the ontology >> language. >> >> 2. The homework would be to integrate this expressive language with > > the kind of human-oriented interface being developed in the >> context of the DARPA RKF project, in which a 'graphic' interface >> allows >> subject-mater experts who know zilch about KR or logic to fairly >> easily, with some training and practice, create large, complex >> ontologies in man-month timeframes. Hopefully, this could be >> designed in such a way that later work could build on earlier >> work, in the sense that the concepts developed in earlier >> ontologies can be >> utilised in later ones. >> >> 3. In a parallel effort, a fairly small team of ontological >> engineers can systematically collect existing useful ontologies of >> broad >> utility - of which there are now several hundred, covering topics >> such as: time-intervals and calendars, part/whole mereological >> theories, spatial reasoning, order-sensitive reasoning, theories of >> networks and reticulations, process and action descriptions, >> industrial processes, etc. etc. . Some of these are more 'abstract' >> than others; the sources range from philosophical analyses to >> industrial standards organizations; but they can all be put into a >> common framework, and indeed are being so put into a subset of >> ISO-KIF by a small team of people at Teknowledge, right now. >> >> All of this is actual work in progress, and could be adopted and >> put into the service of the WebOnt effort immediately. It seems >> silly to ignore it. >> >> Pat Hayes >> -- >> -------------------------------------------------------------------- >> - IHMC (850)434 8903 home >> 40 South Alcaniz St. (850)202 4416 office >> Pensacola, FL 32501 (850)202 4440 fax >> phayes@ai.uwf.edu >> http://www.coginst.uwf.edu/~phayes >> > >-----BEGIN PGP SIGNATURE----- >Version: PGP 6.5.3 > >iQA/AwUBPAfgERdTablCCzU/EQJ1iQCgsfTOOLKL6z17r5Wqo5zOgxcAsEwAnRWR >9rm8YohGoVasMcCSPE2w7YMV >=lIOT >-----END PGP SIGNATURE----- -- --------------------------------------------------------------------- IHMC (850)434 8903 home 40 South Alcaniz St. (850)202 4416 office Pensacola, FL 32501 (850)202 4440 fax phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Thursday, 6 December 2001 11:41:42 UTC