A study with follow-up interviews of services for homeless and mentally ill persons (original sample of 163) had a very high success rate of over 70% in tracking this difficult to locate population. Techniques for locating clients are presented, as identified by a focus group of five researchers. (SLD)

Approaches to the practical problems of finding former offenders and making them want to participate in a study are described for a study of desistance from crime. In the example, a success rate of 78% was achieved for a sample of 50 former offenders. Attention to individual circumstances is critical. (SLD)

Tracking and two statistical methods (probability weighting and sample selection modeling) were studied as ways to minimize bias attributable to sample attrition in school-based studies. Data on student smoking from 30 middle schools illustrate that sample weighting yields the best results, with estimates superior to sample selection and much less…

Simple methods for detecting attrition (nonresponse) in longitudinal evaluations are reviewed, focusing on regression-based analyses of data from a longitudinal evaluation. The approaches are illustrated with data from the Fort Bragg Evaluation, an evaluation of a major demonstration in children's mental health services. (SLD)

A meta-analysis of school-based substance abuse prevention studies revealed that the mean proportion of subjects retained dropped from 81.4 percent at the three-month followup to 67.5 percent at the three-year followup. Researchers should interpret their results in light of these normative data and adopt second-effort strategies to reduce…

Problems with conducting randomized field experiments in education are explored. Focus is on problems encountered while evaluating a group of dropout prevention projects. Project planners were asked to manipulate the subject eligibility criteria until they identified as eligible three to four times as many students as they could serve. They were…

Legislative mandates in California and at the federal level require written parental consent for surveys of children and youth on: sexual behavior and attitudes; illegal, antisocial and criminal behavior; and psychological problems. Active parental refusal and nonresponse to requests for permission threaten the generalizability of information…

Scientific research that is conducted without the structure of a supporting scientific paradigm should be labeled pseudoscience in that such research is deceptive or false science. It is argued that much of the research in educational technology is pseudoscience, with the focus on learner control research. Learner control is the design feature of…

The National Education Longitudinal Study of 1988 (NELS:88) serves as an example of how three specific problems of representativeness in a longitudinal study may be approached and overcome. NELS:88 was designed to provide longitudinal data about the educational transitions experienced by students as they leave eighth grade and move through high…