This "What Works Clearinghouse Procedures and Standards Handbook (Version 3.0)" provides a detailed description of the standards and procedures of the What Works Clearinghouse (WWC). The remaining chapters of this Handbook are organized to take the reader through the basic steps that the WWC uses to develop a review protocol, identify…

Among the many problems faced by family researchers in conducting experimental research in field settings is that posed by nonequivalent and intact treatment and control groups. Nonequivalence refers to the assignment of individuals to treatments on a nonrandom basis, thus generating treatment groups with different expected values on one or more…

When two groups, initially dissimilar, undergo different treatments, can subsequent differences be partitioned in such a way that the difference between the two treatments is unbiased? This is the central problem of this paper, and it is confronted by the examination of two levels of information using a Follow Through Evaluation. The first…