Evaluation Review current issue

Using Tax Parcels to Select a Location-Based Sample: An Illustration That Examines Residents' Awareness of Sex Offenders in Neighborhoods

Craun, S. W., Freisthler, B. — 2008-06-30

Social science research is increasingly considering place when examining social programs and policies with a spatial component. A specific research challenge involving spatial policies is how to select a sample of individuals based on their geographic locations. This article illustrates the use of geographic information systems, tax parcels, and mail surveys to target residents in varied geographic areas. A provided example demonstrates how researchers obtained a sample of respondents living within one tenth of a mile of multiple registered sex offenders. The challenges of using tax parcels to obtain addresses for apartments and mobile home parks are also explored.

Active Parental Consent in School-Based Research: How Much Is Enough and How Do We Get It?

Esbensen, F.-A., Melde, C., Taylor, T. J., Peterson, D. — 2008-06-30

Active parental consent policies have been blamed for low participation rates and selection bias (i.e., loss of "high-risk" youths) in school-based studies. In this article, the authors describe active consent procedures that produced an overall active consent rate of 79% in a sample of more than 4,500 middle school students attending 29 schools in seven cities across the United States. Consent rates, however, varied considerably both within and between schools. To better understand factors associated with active parental consent rates, the authors examined district-level, school-level, and teacher-specific effects on consent rates.

What Respondents Really Expect From Researchers

Kolar, T., Kolar, I. — 2008-06-30

This article addresses the issue of falling response rates in telephone surveys. To better understand and maintain respondent goodwill, concepts of psychological contract and respondent expectations are introduced and explored. Results of the qualitative study show that respondent expectations are not only socially contingent but also ego-expressive, utilitarian, pleasurable, and epistemic by nature. Although results are reassuring in terms of commercialization of the psychological contract, they indicate some radical changes that are needed for the respondents to accept its continuation. The article discusses several practical and theoretical implications of such changes and suggests a series of corresponding propositions aimed at facilitating and inspiring future developments in this field.

Weighting Regressions by Propensity Scores

Freedman, D. A., Berk, R. A. — 2008-06-30

Regressions can be weighted by propensity scores in order to reduce bias. However, weighting is likely to increase random error in the estimates, and to bias the estimated standard errors downward, even when selection mechanisms are well understood. Moreover, in some cases, weighting will increase the bias in estimated causal parameters. If investigators have a good causal model, it seems better just to fit the model without weights. If the causal model is improperly specified, there can be significant problems in retrieving the situation by weighting, although weighting may help under some circumstances.

Erratum

2008-06-30