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From: ht@epistemi.UUCP (Henry Thompson)
Newsgroups: net.ai
Subject: Re: Top down vs Bottom up?
Message-ID: <338@epistemi.UUCP>
Date: Wed, 20-Nov-85 11:42:28 EST
Article-I.D.: epistemi.338
Posted: Wed Nov 20 11:42:28 1985
Date-Received: Sat, 23-Nov-85 10:14:14 EST
References: <13220@rochester.UUCP>
Reply-To: ht@epistemi.UUCP (Henry Thompson)
Organization: Epistemics, Edinburgh U., Scotland
Lines: 18

I don't know about vision, but in natural language and/or
speech processing work, I find it more useful to consider the
instructive versus selective interaction question as opposed
to the top-down versus bottom-up one.

Making that shift places the emphasis where I think it belongs,
namely on what the relationship is between various 'levels' of
processing, and avoids the implication often conveyed by the use
of the appelation 'bottom-up' that no 'higher level' processing
is involved at all.

If I understand your final point correctly, it is that you
don't see any difference in outcome turning on the question of
what sort of cross-level interaction is employed.  I don't know of
any counter-examples, but it still seems to me that more than just
efficiency/resource issues are involved - the intellectual style
of the two positions is quite different, and this encourages different
sorts of exploration...