This paper is concerned with fuzzy modeling in some reduction methods of in
ference rules with gradient descent. Reduction methods are presented, which
have a reduction mechanism of the rule unit that is applicable in three pa
rameters-the central value and the width of the membership function in the
antecedent part, and the real number in the consequent part-which constitut
e the standard fuzzy system. In the present techniques, the necessary numbe
r of rules is set beforehand and the rules are sequentially deleted to the
prespecified number. These methodes indicate that techniques other than the
reduction approach introduced previously exist. Experimental results are p
resented in order to show that the effectiveness differs between the propos
ed techniques according to the average inference error and the number of le
arning iterations.