This publication is primarily designed for educational practitioners who possess little or no training in conducting mail surveys or have not kept current on the present state of the art of survey methods and techniques. It is also intended to be a checking and comparing aid to ensure that important research considerations are taken into account.…

When two groups, initially dissimilar, undergo different treatments, can subsequent differences be partitioned in such a way that the difference between the two treatments is unbiased? This is the central problem of this paper, and it is confronted by the examination of two levels of information using a Follow Through Evaluation. The first…