Xref: utzoo comp.ai:3163 talk.philosophy.misc:1876 sci.lang:3996 Path: utzoo!attcan!uunet!husc6!bloom-beacon!bu-cs!mirror!rayssd!raybed2!linus!mbunix!bwk From: bwk@mbunix.mitre.org (Barry W. Kort) Newsgroups: comp.ai,talk.philosophy.misc,sci.lang Subject: Re: Categorization Summary: Fuzzy Ideas: Inventing the continuum between 0 and 1. Keywords: Crisp Sets and Fuzzy Sets Message-ID: <43780@linus.UUCP> Date: 22 Jan 89 14:48:17 GMT References: <681@cogsci.ucsd.EDU> <2959@uhccux.uhcc.hawaii.edu> <2899@xyzzy.UUCP> Sender: news@linus.UUCP Reply-To: bwk@mbunix.mitre.org (Barry Kort) Organization: Neurotic Netware, Dendrite Faults, NV Lines: 26 In article harnad@elbereth.rutgers.edu (Stevan Harnad) writes: > To me, to categorize is to sort instances in a reliable, > correct, objective, all-or-none fashion. If it's not reliable, > correct or all-or-none, it's not categorization (or not > categorical to the degree that it's not reliable, correct or > all-or-none). If it's not objective, it's subjective; then you > can call it what you like, because I have no idea what's being > sorted, and on what basis. This discussion reminds me of the notion of Fuzzy Sets, as introduced by Berkeley's Lofti Zadeh some twenty years ago. By way of contrast, Stanford's Tom Cover coined the phrase Crisp Sets to emphasize Stevan's concept of reliable all-or-none categorization. I like the notion of Fuzzy Sets, because they better capture our human nature of disagreeing on the boundaries of set membership. But I also like Fuzzy Sets because they map into Fuzzy Logic much the way Crisp Sets map into Boolean Logic. Fuzzy Logic models the mental state associated with such vague and confusing ideas. When we have no clear idea, but we have something more than "no idea", we have a fuzzy idea. --Barry Kort