Xref: utzoo comp.ai:3040 talk.philosophy.misc:1805 sci.lang:3877 Path: utzoo!attcan!uunet!lll-winken!lll-ncis!helios.ee.lbl.gov!nosc!humu!uhccux!lee From: lee@uhccux.uhcc.hawaii.edu (Greg Lee) Newsgroups: comp.ai,talk.philosophy.misc,sci.lang Subject: Re: Categorization Message-ID: <2980@uhccux.uhcc.hawaii.edu> Date: 10 Jan 89 16:46:50 GMT References: Organization: University of Hawaii Lines: 35 From article , by harnad@elbereth.rutgers.edu (Stevan Harnad): " ... " The problem is that this kind of research and this kind of conclusion " simply changes the subject: Instead of trying to find (C) the " representation that will allow us to perform X/non-X categorization " in the myriad cases where we can indeed do it in a reliable, all-or-none " fashion, it turns instead to (T) judgments of typicality and to " introspections about how we categorize, and then offers T as if it " were the mechanism for C, whereas T simply PRESUPPOSES a mechanism for " C, without specifying it or even realizing that the question has been " begged! Why does T presuppose a mechanism for C? " Worse yet, a T-mechanism is put forward as a C-mechanism, a " job it certainly can't do! Why not? If 40%-X and 89%-X are grades, then so is 100%-X a grade. If you have T, C can be described as a special case of it. "... One thing is sure: in all the cases where categorizers are " demonstrably able to categorize their input in a reliable, correct " all-or-none fashion, there NECESSARILY exists a set of features in the input " that is jointly SUFFICIENT to generate the successful performance, and ... That's sure only if you adopt a notion of feature that is empirically empty. That is, if a feature is any function whatever of perceptible things in the input (past and present), including perhaps disjunctions, weightings, etc., then you could say that since someone performed a categorization, there must have been some things he noticed, a "feature", that allowed him to do so. This empty argument might reasonably be taken to be a reductio ad absurdum for allowing anything at all to count as a feature. Greg, lee@uhccux.uhcc.hawaii.edu