You might generalize "Knowledge Bases" to "Similarity Analysis". It is
possible, for example, to use the stored idea of a "fork" in chess in
other games, or on the battlefield. This, in turn, generalizes to
categories and symbols - "when are two things the same" is "when are
they in the same category" is "when do I use the same word". And this,
in turn, shares a fuzzy boundary with perception and search trees - that
is, an analogy is a kind of high-level perception, and that analogy may
be created by a search tree that tries to unify low-level similarities
in all the possible ways. (Actually, I don't know how symbols and
analogies work.)
Nevertheless, I think that "Similarity Analysis" remains distinct. That
the various strategies may be composed of each other (at different
levels) does not obviate their usefulness as heuristics.
--
sentience@pobox.com Eliezer S. Yudkowsky
http://pobox.com/~sentience/AI_design.temp.html
http://pobox.com/~sentience/sing_analysis.html
Disclaimer: Unless otherwise specified, I'm not telling you
everything I think I know.