This article describes the methodology used in the 2007 U.S. National Roadside Survey to estimate the prevalence of alcohol- and drug-impaired driving and alcohol- and drug-involved driving. This study involved randomly stopping drivers at 300 locations across the 48 continental U.S. states at sites selected through a stratified random sampling…

Research synthesis of evaluation findings is a multistep process. An investigator identifies a research question, acquires the relevant literature, codes findings from that literature, and analyzes the coded data to estimate the average treatment effect and its distribution in a population of interest. The process of estimating the average…

The study dealt with a research environment in which the treatment effect is heterogeneous, and in which individuals use their assessments of the treatment effect to decide whether or not to enroll in an intervention program. In this article, a new methodology is proposed for examining the validity of the specified research environment in a given…

Evaluations that combine social science and law have tremendous potential to illuminate the effects of governmental policies and yield insights into how effectively policy makers' efforts achieve their aims. This potential is infrequently achieved, however, because such interdisciplinary research contains often overlooked substantive and…

Longitudinal research designs involve data collection at multiple time points to measure change over time. Therefore, identification of the same respondents is essential at each time point so that data from the same respondents can be matched for comparison over time. Subject-generated identification codes permit an anonymous means to track…

Propensity score analysis is a relatively recent statistical innovation that is useful in the analysis of data from quasi-experiments. The goal of propensity score analysis is to balance two non-equivalent groups on observed covariates to get more accurate estimates of the effects of a treatment on which the two groups differ. This article…

Discusses advantages of randomized experiments and key issues raised in this special issue. Focuses on growth and decrease in the use of randomized experiments by the California Youth Authority, the U.S. National Institute of Justice, and the British Home Office. Calls for increased recognition of the importance of randomized experiments. (SLD)

Describes the randomized field trials conducted by the California Youth Authority in the 1960s and 1970s and discusses why such rigorous tests were used and why they eventually came to be used less often. (SLD)

Discusses the contrast between the frequency of randomized clinical trials in the health sciences and the relative famine of such studies in criminology. Attributes this difference to the contexts in which research is done and the difference in the status of situational research in the two disciplines. (SLD)

Discusses potential sources of self-selection bias in quasi-experimental evaluations of whole-school reform and considers how individual school-level data might be used to provide valid impact estimates. Develops an instrumental variable strategy that can be used to improve on common value-added estimators when only post-treatment measures are…

Alcohol use is highly prevalent among U.S. college students, and alcohol-related problems are often considered the most serious public health threat on American college campuses. Although empirical examinations of college drinking have relied primarily on self-report measures, several investigators have implemented field studies to obtain…

Introduces an new approach for measuring the impact of whole school reforms. The approach, based on "short" interrupted time-series analysis, is explained, its statistical procedures are outlined, and how it was used in the evaluation of a major whole-school reform, Accelerated Schools is described (H. Bloom and others, 2001). (SLD)

Although some argue that randomization of treatments or interventions violates accepted norms of conduct of social science research, this article makes the case that there is a moral imperative for the conduct of randomized experiments in crime and justice studies. (SLD)

Presents conversion factors to be used to translate the quality of the respective contraception methods distributed to a single measure of protection for calculating couple-years of protection in family planning studies. Discusses the implications for the evaluation of family planning programs. (SLD)

Until the past few years, our nation's approach to designing federal programs for preschool-age children lacked coherence and paid little attention to what had worked (and not worked) in the past. In this article, the authors propose that credible information useful for designing effective programs will require the ongoing, systematic development…