We present two fully sequential indifference-zone procedures to select the best system from a number of competing simulated systems when best is defined by maximum or minimum expected performance. These two procedures have parabola shaped continuation regions rather than triangular continuation regions employed in several papers. The procedures we present accommodate unequal and unknown varianc...

SUMMARY Suppose one has k populations and wishes eventually to choose the "best" one. It is often desirable to use a multi-stage experiment, where at each stage, at least t (~l) populations are selected for further study. This paper is concerned with selecting at least t(~2) populations, presenting generalizations of two methods in existence for t = 1. One method has as its goal the selection o...