This study uses an ecological framework to examine how adolescents' perceptions of school climate in 6th grade covary with the probability and frequency of their engagement in problem behaviors in 7th and 8th grades. Tobit analysis was used to address the issue of having a highly skewed outcome variable with many zeros and yet account for…

The authors extended previous research by 2 of the authors who conducted a study designed to predict the successful completion of students enrolled in an actuarial program. They used logistic regression to determine the probability of an actuarial student graduating in the major or dropping out. They compared the results of this study with those…

Objective: This study examined the associations between college students' self-reported alcohol use and corresponding collateral reports and identified factors that influence agreement between both sets of reports. Participants/Methods: Subject-collateral pairs (N = 300) were recruited from undergraduate psychology courses. Results: Data yielded…

Most treatments of indirect effects and mediation in the statistical methods literature and the corresponding methods used by behavioral scientists have assumed linear relationships between variables in the causal system. Here we describe and extend a method first introduced by Stolzenberg (1980) for estimating indirect effects in models of…

This study investigated certified rehabilitation counselors' (CRCs) attitudes, knowledge, and comfort in addressing disability and sexuality issues. One hundred ninety-nine CRCs completed a modified version of the "Knowledge, Comfort, Approach and Attitudes toward Sexuality Scale" to determine the effect of knowledge and attitudes on level of…

Are economic resources related to relationship quality among young couples, and to what extent does this vary by relationship type? To answer these questions, we estimated regression models predicting respondent reports of conflict and affection in cohabiting and married partner relationships using the National Longitudinal Study of Youth, 1997…

The relationship between complexity and usefulness can be captured by a U-shaped curve. This comment explores that relationship. Complexity may be useful for one of the main aims of developmental psychology (causal inference) but not for another (description of developmental phenomena). Currently, developmentalists conduct complex analyses that…

Mixture item response theory models have been suggested as a potentially useful methodology for identifying latent groups formed along secondary, possibly nuisance dimensions. In this article, we describe a multilevel mixture item response theory (IRT) model (MMixIRTM) that allows for the possibility that this nuisance dimensionality may function…

Word and nonword identification skills were examined in a sample of 80 elementary school age students with mild intellectual disabilities and mixed etiologies who were described as struggling to learn to read by their teachers. Performance on measures of receptive and expressive vocabulary, measures of phonological awareness, and measures of word…

To investigate the pedagogical effectiveness of oral corrective feedback (CF) on target language development, we conducted a meta-analysis that focused exclusively on 15 classroom-based studies (N = 827). The analysis was designed to investigate whether CF was effective in classroom settings and, if so, whether its effectiveness varied according…

The goal of this article is to present a series of conceptual, statistical, and practical issues in the modeling of multi-level dyadic data. Distinctions are made between distinguishable and undistinguishable dyads and several types of independent variables modeled at the dyadic level of analysis. Multi-level modeling equations are explained in a…

This study used data from the Panel Study of Income Dynamics (PSID) on two generations of African American women who gave birth from 1967 to 2005 to describe changing relationships between marital status and low birth weight (LBW) across the generations. An increasing protection of marriage on infant LBW across the two generations was found after…

Physical rehabilitation day hospitals are widely used community-based services designed to meet the medical and rehabilitation needs of older people. While there is evidence for the effectiveness of these services, concerns about the shortcomings of how this is measured have led to the recommendation that the achievement of individually tailored…

Objective: Evaluate a new 5-step method for testing mediators hypothesized to account for the effects of depression prevention programs. Method: In this indicated prevention trial, at-risk teens with elevated depressive symptoms were randomized to a group cognitive-behavioral (CB) intervention, group supportive expressive intervention, CB…

The aim of the study was to investigate the relationship between the Flynn effect and the effects of age differences between siblings on the intelligence difference between them. In Norway, the secular trends in intelligence-test score means vary both in magnitude and direction. We identified three periods: one period where the mean intelligence…