Treatment effect estimates from a "regression discontinuity design" (RDD) have high internal validity. However, the arguments that support the design apply to a subpopulation that is narrower and usually different from the population of substantive interest in evaluation research. The disconnect between RDD population and the…

Rapidly declining response rates and the associated threat of nonresponse bias call into question the validity of data obtained through telephone surveys, a tool often used in evaluation. This article explores changes in nonresponse bias over time by examining three data points (1991, 1996, and 2002) from an annual household telephone survey…

The third-year evaluation of the federally funded Washington, D.C. voucher program shows that low-income students offered vouchers in the first two years of the program had modestly higher reading scores after three years but showed no significant difference in mathematics. Students were randomly assigned to treatment and control groups, and the…

A report from the School Choice Demonstration Project examines issues concerning the funding formula used for the Milwaukee Parental Choice Program (MPCP). It finds that the program generates a net saving to taxpayers in Wisconsin but imposes a significant fiscal burden on taxpayers in Milwaukee. However, these findings depend significantly on how…

"How New York City's Charter Schools Affect Achievement" estimates the effects on student achievement of attending a New York City charter school rather than a traditional public school and investigates the characteristics of charter schools associated with the most positive effects on achievement. Because the report relies on an…

A strategy proposed by T. Cook and D. Campbell (1979) was used to investigate attrition in a community-based literacy program, focusing on 287 Head Start families. Data revealed interactions among intervention program-centered characteristics and person-centered characteristics that have implications for study validity and generalizability.…

An attempt was made to estimate possible bias in terms of Normal Curve Equivalent (NCE) gains of Elementary Secondary Education Act (ESEA) Title I projects. Twenty-two state Title I reports for 1978 were examined. The analyses presented were directed at two major sources of bias: bias due to errors in local implementation of models, and bias due…

Methods of using simplified time series analysis (STSA) in evaluating clinical programs are discussed. STSA assists in addressing problems of attrition/augmentation of subjects in programs with changing populations. Combining individually calculated "C" statistics in a simple aggregate analysis of restraint usage by nursing home staff…

Seven qualitative issues associated with randomization that have the potential to weaken or destroy otherwise sound experimental designs are reviewed and illustrated via actual field experiments. Issue areas include ethics and legality, liability risks, manipulation of randomized outcomes, hidden bias, design intrusiveness, case flow, and…

A new report published by the Manhattan Institute for Education Policy, "The Effect of Special Education Vouchers on Public School Achievement: Evidence from Florida's McKay Scholarship Program," attempts to examine the complex issue of how competition introduced through school vouchers affects student outcomes in public schools. The…

Using examples from evaluations of the Emergency School Aid Act (ESAA) Basic Grants Program, the ESAA Pilot Program, and the sustaining effects of compensatory education programs, school and student attrition are discussed. As in the example cases, appreciable attrition can be expected in most longitudinal studies. The possible effects of this…

Meta-analysis of Title I program evaluations shows the norm-referenced model overestimates positive effectiveness; while the regression-discontinuity design underestimates it. Potential biases include residual regression artifacts, attrition and time-of-testing problems in the norm-referenced design, and assignment, measurement, and data…

Because research synthesis enables one to determine either the overall effectiveness of a particular treatment or the relative effectiveness of different types of treatments, it is becoming increasingly popular as a tool in program evaluation. Numerous methodological problems arise, however, when research synthesis is applied to studies conducted…

An examination was made of Federal program statistics on vocational education during the past 10 years by the Bureau of Occupational and Adult Education of the U. S. Office of Education and the National Center for Education Statistics of the U. S. Department of Education. The study found that despite a mandate for reform, the National Center's…

A solution to the problem of specification error due to excluded variables in statistical models of treatment effects in nonrandomized (nonequivalent) control group designs is presented. It involves longitudinal observation with at least two pretests. A maximum likelihood estimation program such as LISREL may provide reasonable estimates of…