Approaches to Evaluating Welfare Reform: Lessons from Five State Demonstrations. A. ADEQUACY OF SAMPLE SIZE


In evaluating welfare reform, it is important to have adequate samples to learn about the effectiveness of the program. The larger the sample, the more precisely the impacts of the program can be estimated. The larger the sample, however, the more costly the implementation of the welfare reform demonstration. In random-assignment evaluations, administering two sets of policies for research is the major cost for most states; at least some administrative costs (such as training staff members to handle both policies, monitoring random assignment) will increase with sample size. Federal officials, in preparing the waiver terms and conditions, have specified minimum sample sizes, with some variation according to the particular needs and objectives of the evaluation. States have been encouraged to exceed the minimum if possible.