A Kiefer-Wolfowitz or simultaneous perturbation algorithm that uses either
one-sided or two-sided randomized differences and truncations at randomly v
arying bounds is given in this paper. At each iteration of the algorithm on
ly two observations are required in contrast to 2l observations, where l is
the dimension, in the classical algorithm, The algorithm given here is sho
wn to he convergent under only some mild conditions. A rate of convergence
and an asymptotic normality of the algorithm are also established.