This article discusses the use of propensity scoring in experimental program evaluations to estimate impacts for subgroups defined by program features and participants' program experiences. The authors discuss estimation issues and provide specification tests. They also discuss the use of an overlooked data collection design--obtaining predictions…

In an overview of single-case methodology, the potential utility of A-B-A and multiple baseline designs for evaluating social programs is discussed. Validity factors and cost-effectiveness are considered, showing that these designs are viable alternative methods where traditional randomized group designs are infeasible. (Author/CM)