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…

Drug studies are often cited as the best exemplars of evaluation design. However, many of these studies are seriously biased in favor of positive findings for the drugs evaluated, even to the point where dangerous effects are hidden. In spite of using randomized designs and double blinding, drug companies have found ways of producing the results…

The gold standard in making causal inference on program effects is a randomized trial. Most randomization designs in education randomize classrooms or schools rather than individual students. Such "clustered randomization" designs have one principal drawback: They tend to have limited statistical power or precision. This study aims to…

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…

One source of bias, regression artifacts, in program evaluations that use regression discontinuity design is identified, and its importance is discussed. A method is suggested for its correction. Although use of this method does not solve the problem of selection bias, it does improve the reliability of nonexperimental methods. (SLD)

The Comparing Options in Secondary Mathematics: Investigating Curriculum (COSMIC) project is a longitudinal study of student learning from two types of mathematics curricula: integrated and subject-specific. Previous large-scale research studies such as the National Assessment of Educational Progress (NAEP) indicate that numerous variables are…

"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…

Assessment of welfare gains from a targeted social program can be seriously biased unless the endogeneity of program participation is addressed. Bias comes from two sources of placement endogeneity: the purposive targeting of geographic areas, and the targeting of individual recipients within selected areas. Partial decentralization of program…

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…

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…

A Friedman Foundation report attempts to find empirical support for the contention that competition from private schools, through voucher programs, improves the effectiveness of public schools. In the first year of Ohio's new EdChoice voucher program, the report claims to have found substantial academic gains at public schools exposed to the…

A beverage-server intervention project at two West Coast Navy bases that attempted to reduce levels of alcoholic intoxication via policy changes and server training is described. Data obtained via interviews and structured observations of 1,511 club customers indicate methodological bias and self-selection effects. Bias adjustments were performed…