This paper provides rigorous evidence (for 12,130 participants in a series of naturally occurring randomized lotteries) that a large‐scale high school reform initiative (New York City's creation of 100+ small high schools of choice between 2002 and 2008) can markedly and consistently increase...

We explore the use of instrumental variables (IV) analysis with a multisite randomized trial to estimate the effect of a mediating variable on an outcome in cases where it can be assumed that the observed mediator is the only mechanism linking treatment assignment to outcomes, an assumption...

This article presents lessons learned from an innovative employment and training program for dislocated workers—persons who have lost stable, long-term jobs due to changing technology and/or increased international competition. Because the program was conducted as a randomized experiment,...

This article has two related purposes. One is to extend the methodology for evaluating correctional programs. Two aspects of this methodology are considered: (1) the measurement of a program's ability both to prevent and to postpone criminal behavior, and (2) the use of cost-effectiveness...

This article examines household participation in the national Section 8 Existing Housing Program funded by the U.S. Department of Housing and Urban Development. It develops a prototype for evaluating a multistage selection process which requires potential recipients to pass through several...

This article presents estimates of program-induced, post-program earnings gains for men and women who enrolled in CETA between January 1975 and June 1976. Data for the analysis were obtained from the Continuous Longitudinal Manpower Survey for CETA participants with corresponding comparison...

This article examines how to estimate the effect of a program in the presence of no- shows—persons who are assigned to the program but do not participate. The article briefly discusses the methodological problems involved, describes two current experimental evaluations that are subject to...

The present article introduces a new approach for measuring the impacts of whole-school reforms. The approach is based on “short†interrupted time-series analysis, which has been used to evaluate programs in many fields. The approach is used to measure impacts on three facets of...

This article describes a simple way to assess the statistical power of experimental designs. The approach presented is based on the concept of a minimum detectable effect, which, intuitively, is the smallest true impact that an experiment has a good chance of detecting. The article illustrates...