There are many situations where random assignment of participants to treatment and comparison conditions may be unethical or impractical. This article provides an overview of propensity score techniques that can be used for estimating treatment effects in nonrandomized quasi-experimental studies. After reviewing the logic of propensity score…

This article investigates three types of stage-sequential growth mixture models in the structural equation modeling framework for the analysis of multiple-phase longitudinal data. These models can be important tools for situations in which a single-phase growth mixture model produces distorted results and can allow researchers to better understand…

Over a two-year period this study examined the relationship of two levels of supervision with both the job performance and weekly earnings of the hard-core unemployed (HCU). First- and second-level supervisors were measured on consideration, initiating structure, and social insight. After six months on the job the HCU's perceptions of their…

Despite the growing accumulation of studies attesting to the association between life events and illness, either physical or mental, a number of critical methodological and conceptual issues are considered not to permit any clear answer to the basic questions regarding the importance of the role these events play in the etiology of such disorders.…

Stochastic difference equations of the Box-Jenkins form provide an adequate family of models on which to base the stochastic theory of human growth processes, but conventional time series identification methods do not apply to available data sets. A method to identify structure and parameters of stochastic difference equation models of human…

Project TALENT is a large-scale, long-range educational research effort aimed at developing methods for the identification, development, and utilization of human talents, which has involved some 440,000 students in 1,353 public, private, and parochial secondary schools in all parts of the country. Data collected through teacher-administered tests,…

In December 1993, children who were in grade 3 in the Trenton Public Schools (New Jersey) in 1985-86 will take a high-risk writing proficiency test to determine whether they will graduate from high school. An emerging study of the writing of the Class of 1995 in Trenton is described as students move toward that test. The activity of studying…