home *** CD-ROM | disk | FTP | other *** search
- Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU
- Path: sparky!uunet!spool.mu.edu!howland.reston.ans.net!paladin.american.edu!auvm!UIUC.EDU!G-CZIKO
- Return-Path: <@VMD.CSO.UIUC.EDU:g-cziko@uiuc.edu>
- X-Sender: cziko@ux1.cso.uiuc.edu (Unverified)
- Message-ID: <199301102141.AA24950@ux1.cso.uiuc.edu>
- Newsgroups: bit.listserv.csg-l
- Date: Sun, 10 Jan 1993 15:41:31 -0600
- Sender: "Control Systems Group Network (CSGnet)" <CSG-L@UIUCVMD.BITNET>
- From: "Gary A. Cziko" <g-cziko@UIUC.EDU>
- Subject: Generative vs. Explanatory
- Lines: 56
-
- [from Gary Cziko 930110.2106]
-
- I've been enjoying the discussion between Greg Williams, Bill Powers, and
- Rick Marken, apparently originally sparked by my 3 Pencils adaptation of
- Rick's research.
-
- I certainly don't have time to get heavily involved in this, but I want to
- make a quick comment on Greg Williams's (930109) saying:
-
- >f is supposed to USE observables only, like cursor position and handle
- >velocity. Of course, f itself is a model, and I suppose you could then argue
- >that behaviorists actually propose generative models if they do any more than
- >curve-fitting (per the above, the Newtons of their day!?!?). Bill argues below
- >that behaviorists do NOT propose generative models, but I suppose that he is
- >claiming that all they ever do is curve-fit. And here I am trying to claim
- >that at least some behaviorists go beyond curve-fitting (like Newton did) and
- >yet use only observables in their "models" -- which aren't the sorts of models
- >I've always been thinking underlying generative models to be. I think curve-
- >fitting doesn't count as making generative models, but I'm not convinced that
- >hypothesizing functions containing only observables does count as making
- >underlying generative models.
-
- Perhaps we need to make a distinction between generative and explanatory.
- Curve fitting can never be based solely on the observed data as there are
- an infinite number of curves that can fit any collection of data points.
- The functional relationships obtained by curve must therefore always go
- beyond the data and the resulting hypothesized relatioship can also be used
- to make predictions which have not yet been observed. Presumably, more
- data will help to fine-tune the hypothesized relationship by showing that
- it is in some ways invaled and new relationship is then hypothesized which
- did everything the old could do and some things it couldn't.
-
- But such a hypothesized relationship, although generative, doesn't explain
- WHY the relationship exists. To explain we would have to move to an
- underlying level, from psychology to physiology, for instance.
-
- So perhaps a difference between behaviorism and PCT is that while both try
- to be generative, only PCT tries to be explanatory. To make predictions we
- need a generative theory. To answer "why" something happens, we need an
- explanatory one.
-
- It also appears to me that Chomsky's grammar is also generative but not
- explanatory since he uses no physiology in his theorizing. Would Avery and
- Bruce agree with this?
-
- Where does this leave Newton?--Gary
-
- ------------------------------------------------------------------
- Gary A. Cziko Telephone: 217-333-8527
- Educational Psychology FAX: 217-244-7620
- University of Illinois E-mail: g-cziko@uiuc.edu
- 1310 S. Sixth Street Radio: N9MJZ
- 210 Education Building
- Champaign, Illinois 61820-6990
- USA
- ------------------------------------------------------------------
-