Background: Impact evaluations draw their data from two sources, namely, surveys conducted for the evaluation or administrative data collected for other purposes. Both types of data have been used to estimate program impacts. This is an introductory essay to a Special Issue entitled “Do the...

This paper describes, somewhat overlapping, types of flaws that have occurred in social experiments. Each flaw is illustrated with examples from previous experiments. Some of these problems result in minor hurdles, while others cause experiments to fail — that is, the experiment is unable to...

When evaluating a pilot or demonstration program, there are risks from drawing inferences from a single test. This paper reviews the experiences of replication efforts from demonstrations using randomized controlled trials in the initial evaluation and the replications. Although replications of...

This paper reviews the use of multiple trials in evaluating social programs. We define multiple trials to include both conducting evaluations in multiple sites concurrently and replications, where the intervention is replicated in one or more sites after the initial evaluation. After defining...

Both data obtained from surveys and data maintained by government units for administrating programs have been used to track the outcomes of social programs (e.g., earnings, educational achievement, and government benefit receipt) and, hence, to estimate their impacts. Sometimes both have been...