Because studies examining youth drug use often have data with a high proportion of zeros, they often do not meet the assumptions for univariate or linear regression analyses that are typically used. We demonstrate the use of zero-inflated negative binomial regression models to address excessive zeros in drug use frequency on perceptions of…

Although definitions of validity have evolved considerably since L. J. Cronbach and P. E. Meehl's classic (1955) review, contemporary validity research continues to emphasize correlational analyses assessing predictor-criterion relationships, with most outcome criteria being self-reports. The present article describes an alternative way of…

The Department of Health in England released a new health research strategy in 2006 with far-reaching implications for both health research and research management. The explicit policy shift is towards centres of excellence and away from historical block allocations of funding to National Health Service (NHS) healthcare organisations--with these…

Purpose: The success of schools fundamentally depends on teachers' willingness to go above and beyond the call of duty, namely, to exhibit organizational citizenship behaviors (OCBs). Attempts to understand the causes of OCB frequently focus on individual characteristics; only recently have researchers begun to direct their attention to more…

Predictors of language production skills were evaluated in 48 children and adolescents with Down syndrome and compared to 48 children matched for nonverbal mental age and mother's years of education. Comparison of two models found the model that incorporated comprehension performance (as well group membership, chronological age, cognition,…

This document reports on a study undertaken to identify specific behaviors of secondary school principals that are effective or ineffective in promoting positive school characteristics. The researchers first searched the literature to find an organizational model that would take into account the organization's goals, the means for measuring…

Described in the context of a computer simulation are highlights of a program of research focusing on the storage of mathematics problem solving information in young children's memory and the development of such knowledge structures in older children. Specifically discussed are the problem size effect, the network nature of the memory…

The purpose of the School Improvement Model (SIM) Project is to investigate the links between systematically developed teacher performance evaluation, administrator performance evaluation, staff development interventions, and the quality of education as measured by student achievement results. Following the 4th year of the 5-year study,…

Poor health has been implicated as a suppressor of the life satisfaction of older adults. To clarify the contribution of arthritis to this process, functional disability, negative affect, pain, current severity of the disease, self-esteem, perception of general health, and internal health locus of control, were placed within a causal model as…

Explores whether transactional/interactional, environmental, or developmental status models best represent growth from infancy to early childhood. Attempts to identify features of the social environment important for specific developmental outcomes. Observations of interactions between 40 mothers and their three-month-old infants were used to…

Using data describing entry into preschool among children with special needs, this paper introduces the fundamental statistical quantities of event occurrence--hazard and survivor functions. The paper discusses construction of formal statistical models of event occurrence over time, predictors that can be included in hazard models, and importance…

The authors test biosocial models that posit interactions between biological variables (testosterone, estradiol, pubertal status, and pubertal timing) and social context variables (family, peer, school, and neighborhood) in predicting adolescent involvement with cigarettes and alcohol in a sample of 409 adolescents in Grades 6 and 8. Models…

The Health, Education and Welfare (HEW) Office of Youth Development's National Strategy for Youth Development model was promoted as a community-based planning and procedural tool for enhancing positive youth development and reducing delinquency. To test the applicability of the model as a function of delinquency level, the program's Impact Scales…

Discusses results of a meta-analysis which sought to identify those variables found in research as strongly correlated with responsible environmental behavior. Variables found significant were: knowledge of issues; knowledge of action strategies; locus of control; attitudes; verbal commitment; and sense of responsibility. Proposes a model of…

Although the rate of divorce among older Americans has increased steadily, little attention has been paid to late life divorce. To describe the role of age and other factors which might influence adjustment to divorce in later life, data from a larger pilot study were used: 81 divorced persons over the age of 60 completed in-depth, structured…