- From: pat hayes <phayes@ihmc.us>
- Date: Thu, 15 Jan 2004 16:44:12 -0600
- To: Adrian Walker <adrianw@snet.net>
- Cc: public-sws-ig@w3.org, Benjamin Grosof <bgrosof@mit.edu>
>Pat -- > >How about Heflin's Local Closed World paper [1] ? Yes, just what I had in mind. I hereby express public shame at not having noticed it previously. OK, then, my whine below should be to the effect, why aren't the various proponents of nonmon rules, etc., proposing something like this, instead of trying to sell nonmon as though it were some kind of new age logic? Notice that Jeff's proposal gets the basic dynamics exactly right. It is monotonic but it supports (some) closed-world reasoning. The touted advantages of nonmon are really nothing to do with nonmonotonicity as such. Being nonmonotonic, in itself, provides no discernable benefits to anyone. Being able to use closed-world reasoning, unique-name reasoning, default reasoning, etc., in situations where you know they are OK to use, provides great benefits. What we need are ways to be able to take advantage of the computational merits of such efficient reasoning processes, but within a globally monotonic system of information exchange. Ideas like Jeffs are exactly what we need to be seeking here. Arguments which treat 'monotonic' as a generic tar-brush, such as http://ebusiness.mit.edu/bgrosof/paps/beyond-mon-inh-wking-pap-081603.pdf are not; they simply serve to muddy the discussion, cause needless polarization and confusion, and get critical ideas muddled. OK, end of rant. Thanks for the feedback. Pat Hayes >It gets the best of both worlds (:-) , particularly if you combine >it with English-like rules as in the Internet Business Logic system >[2]. > >The rules can conclude things like "assuming that nothing has >changed on this list of URIs, the answer to your question is..." >One can also get an explanation, showing any LCW assumptions made in >getting the answer. I havnt looked at the details, but it sounds very neat. > >Hope this helps. -- Adrian > >[1] http://www.cse.lehigh.edu/~heflin/ > >[2] www.reengineeringllc.com > > >At 02:29 PM 1/15/04 -0600, you wrote: > >>Re. the (forever ongoing and interminable) debate about the merits >>of otherwise of nonmon reasoning. >> >>Bottom line: nonmon reasoning is brittle (by definition) but can be >>very efficient. So when you know it won't break, by all means use >>it. But it seems to me that it is up to its proponents to justify >>or explain how we can have nonmon formalisms being used in a >>Webbish context, where the brittleness (or if you prefer, >>context-sensitivity) seems on the face of it to be an >>unsurmountable barrier to deployment, since there is no way for a >>reader of some nonmon rules to know what the intended context is; >>and when used out of context, nonmon rules are almost always wrong, >>and can produce potentially dangerous errors. (Note, this is only >>referring to the *publication* of nonmon rules on a Web, not to >>their *use* in some application where it is known they are >>appropriate, or one is willing to take the risk of using them in >>any case.) >> >>So far, the only response Ive heard on this point is a kind of >>blustery denial: a claim that the Sweb just isn't going to be like >>the WWWeb, but more like an intranet, where all the users will just >>know, or will be told by the owner, or will agree among themselves >>in managers' meetings, which worlds are closed and which namespaces >>satisfy the unique-names assumption and so on; so the problem will >>be avoided by what might be called Web-external contextual >>agreements. I refuse to take this answer seriously: it seems to me >>to just be a statement to the effect that one is not working on the >>semantic web at all. >> >>Anyone got any other answers? Until someone has, I would suggest >>that all talk about nonmon systems be ruled out of order. Its not >>enough to observe in a general kind of way that nonmon systems are >>useful (no argument) or that they are in widespread use and all the >>best companies have them and they make a lot of money (irrelevant) >>or that they solve this or that famous problem (they usually don't, >>in any case). There is a basic technical issue that needs to be >>addressed. Address it, or else please shut up about them. >> >>Pat >> >>-- >>--------------------------------------------------------------------- >>IHMC (850)434 8903 or (650)494 3973 home >>40 South Alcaniz St. (850)202 4416 office >>Pensacola (850)202 4440 fax >>FL 32501 (850)291 0667 cell >>phayes@ihmc.us http://www.ihmc.us/users/phayes -- --------------------------------------------------------------------- IHMC (850)434 8903 or (650)494 3973 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32501 (850)291 0667 cell phayes@ihmc.us http://www.ihmc.us/users/phayes
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