Sample allocation decisions for program evaluation: a case of multiplicative effect on units due to the developmental initiatives carried out in a phased manner

Evaluation is primarily a measure of the effects and elaboration on the current performance of a program. It facilitates identification and choice of the ways to achieve the intended program objectives. The evaluation includes selection
of samples, as well as collection and analysis of data. This paper discusses the issue of the allocation of samples for the population for which programs have been
implemented in a phased manner. This needs special attention due to the temporal impact of allocations on the successive units. A method of proportional allocation has been proposed for the estimation of the sample size in different
phases under the assumption that the impact of the latter phase is a multiplicative product of constant factor and the former phase.