This publication describes the methods and procedures used for the 2008/18 Baccalaureate and Beyond Longitudinal Study (B&B:08/18). The B&B graduates, who completed the requirements for a bachelor's degree during the 2007-08 academic year, were first surveyed as part of the 2008 National Postsecondary Student Aid Study (NPSAS:08), and then…

Single subject (SS) designs are popular in educational and psychological research. There exist several statistical techniques designed to analyze such data and to address the question of whether an intervention has the desired impact. Recently, researchers have suggested that generalized additive models (GAMs) might be useful for modeling…

This report describes the design, methods, and results of the 2016/20 Baccalaureate and Beyond Longitudinal Study (B&B:16/20) conducted by the U.S. Department of Education's National Center for Education Statistics (NCES). It is the second follow-up with a cohort of bachelor's degree recipients originally identified during the 2015-16 National…

Experience-sampling methods (ESM) enable us to learn about individuals' lives in context by measuring participants' feelings, thoughts, actions, context, and/or activities as they go about their daily lives. By capturing experience, affect, and action "in the moment" and with repeated measures, ESM approaches allow researchers…

Mediation is a causal process that evolves over time. Thus, a study of mediation requires data collected throughout the process. However, most applications of mediation analysis use cross-sectional rather than longitudinal data. Another implicit assumption commonly made in longitudinal designs for mediation analysis is that the same mediation…

The purpose of this paper is to provide a detailed description of the Monitoring the Future research design, including sampling design, data collection procedures, measurement content, and questionnaire format. This study assesses the changing lifestyles, values, and preferences of American youth on a continuing basis. Each year since 1975, at…

E-learning researchers face considerable challenges in creating meaningful and generalizable studies due to the complex nature of this dynamic training medium. Our experience in conducting workplace e-learning research led us to create this guide for planning research on e-learning. We share the unanticipated complications we encountered in our…

Communities That Care (CTC) is a prevention system designed to reduce adolescent substance use and delinquency through the selection of effective preventive interventions tailored to a community's specific profile of risk and protection. A community-randomized trial of CTC, the Community Youth Development Study, is currently being conducted in 24…

Problems in making inferences from a sample to a population and from one cohort to other cohorts are discussed. It is concluded that in most cases a longitudinal design using repeated measures is preferable to an independent samples design. (Author)

The 2004/06 Beginning Postsecondary Students Longitudinal Study (BPS:04/06), conducted for the U.S. Department of Education's National Center for Education Statistics (NCES), collected information about the education and employment experiences of students in the two years following their first enrollment in postsecondary education. The primary…

Factors that influence the sample size necessary for longitudinal evaluations include the nature of the evaluation questions, nature of available comparison groups, consistency of the treatment in different sites, effect size, attrition rate, significance level for statistical tests, and statistical power. (Author/GDC)

This tutorial is concerned with examining how regression to the mean influences research findings in longitudinal studies of clinical populations. In such studies participants are often obtained because of performance that deviates systematically from the population mean and are then subsequently studied with respect to change in the trait used…

The self-selection problem in program evaluation is explored, and two ways of addressing it, covariate control approaches and two-stage sample selection models, are described. A longitudinal study of the effects of participation in Alcoholics Anonymous illustrates both approaches and shows the advantages of the two-step procedure. (SLD)

This paper describes the design of the interdisciplinary study of the growth and development of Dutch children in progress at the University of Nymegen, The Netherlands. Schaie's design is based on a trifactorial model which isolates the contributions to developmental data of the factors age, cohort and time of measurement. (Author/MS)

This report summarizes tasks undertaken to assess the feasibility of a longitudinal analysis of elementary and secondary schools. The initial objective was to see if it was technically possible to analyze overlap samples of schools from the Schools and Staffing Survey (SASS) to produce substantive findings. Over the course of the project various…