Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!bloom-beacon!BOC.RUTGERS.EDU!mohan From: mohan@BOC.RUTGERS.EDU (Sunil Mohan) Newsgroups: comp.ai.digest Subject: Re: Newell's Knowledge Level Message-ID: <19880905045804.9.NICK@HOWARD-JOHNSONS.LCS.MIT.EDU> Date: 5 Sep 88 04:58:00 GMT Sender: daemon@bloom-beacon.MIT.EDU Organization: The Internet Lines: 46 Approved: ailist@ai.ai.mit.edu To: comp-ai-digest@paul.rutgers.edu Path: boc.rutgers.edu!mohan From: Sunil Mohan Newsgroups: comp.ai.digest Subject: Re: Newell's Knowledge Level Date: Sun, 4 Sep 88 11:53 EDT References: <19880903034508.9.NICK@HOWARD-JOHNSONS.LCS.MIT.EDU> Distribution: usa Organization: Rutgers Univ., New Brunswick, N.J. Lines: 34 The Knowledge Based Software Development Environment (KBSDE) group at Rutgers University are strong believers in the separation of the specification of knowledge from the specification of its use. I believe that that is the underlying theme of Newell's "Knowledge Level". Marr has also talked about the specification of a system in different levels, separating knowledge from algorithm from implementation. This allows a partitioning of the concerns involved in developing a system. As a simple example, it allows one to decide whether inability to solve a particular problem is due to lack of knowledge or an inherently `incomplete' algorithm that uses that knowledge. Describing your research along these levels will also help you and the reader decide where the contribution lies. See for example the paper "Learning At The Knowledge Level" by Dietterich (I think). How many levels you choose to have depends entirely on how finely you wish to partition your concerns. There is no "right" partitioning. The eventual aim is clarity. As far as logic belonging at the Knowledge Level is concerned, in so far as logic is used as a declarative specification of knowledge, and its implications, that is the purpose of the knowledge level. I would tend to think that logic may also be used to specify the algorithm at the symbol level, thus allowing the capability of reasoning about the algorithm. I don't know what you mean by "extra-logical". Could you perhaps be taking the terms too literally? Remeber that the Knowledge Level in itself is not interesting. It is interesting because of what it achieves (viz. clarity, focussing attention). Logic is just a specification and reasoning device. Any form of logic should do, so long as you are aware of its capabilities and limitations. _ Sunil