[ont.events] Learning Hard Concepts.

ylfink@water.waterloo.edu (ylfink) (12/13/88)

DEPARTMENT OF COMPUTER SCIENCE
UNIVERSITY OF WATERLOO
SEMINAR ACTIVITIES

ARTIFICIAL INTELLIGENCE SEMINAR

                    -  Friday, December 16, 1988

Professor   Larry   Rendell,   Department  of  Computer
Science,  University  of  Illinois at Urbana-Champaign,
will speak on ``Learning Hard Concepts''.

TIME:                11:30 AM

ROOM:              DC 1304

ABSTRACT

Hard  boolean  concepts  have arbitrary compositions of
conjuncts  and  disjuncts.   Hard  graded  concepts are
arbitrary   functions   having   any   composition   of
disjuncts,  modes, or peaks.  If instances are k-tuples
of  attribute  values  labeled  with (binary or graded)
class  membership  values,  learning  hard  concepts is
uniformly  difficult  for  a  class  of methods that do
``similarity    based    learning''    or   ``selective
induction''.  The problem has been named differently in
different  areas  of  research:  ``curve  fitting'' and
``density     function    estimation''    (statistics),
``discriminant     boundary''     detection    (pattern
recognition), ``finding weights'' (neural systems), and
``concept  learning''  (artificial  intelligence).  The
poor   behavior   of   these  basic  methods  leads  to
techniques  for  the  creation of ``better'' attributes
through    ``constructive   induction.''    This   talk
characterizes  the  problem  and  presents an algorithm
schema designed to use domain knowledge when available.
The  analysis  shows  how  constructive  induction  can
alleviate difficulties of selective induction.