At the same time, federal, state, and local funds for Extension programs are becoming more difficult to secure. Sample size is an important factor to consider in conducting Extension evaluations, because it influences the cost of evaluations and the validity of results obtained.
Larger samples reduce research error, but can be expensive, time-consuming, and often impractical.
Smaller samples, on the other hand, are less expensive but the risk of error is increased and the validity of results can be questioned. When researchers select a particular sample size, they are basically answering two questions. The purpose of this study was to determine the effect of reducing sample size on the results and costs of doing program evaluation. Raw data for both studies were available to the researchers. Davis' regional study covered six state Extension services in the southeastern United States.