Clustering methods are often used in physics education research (PER) to identify subgroups of individuals within a population who share similar response patterns or characteristics. Among these, k-means (or k-modes, for categorical data) is one of the most commonly used clustering methods in PER. This algorithm, however, is distance-based rather…

We analyzed stimulus class formation in a human study and in a connectionist model (CM) with a yes/no procedure, using compound stimuli. In the human study, the participants were six female undergraduate students; the CM was a feed-forward back-propagation network. Two 3-member stimulus classes were trained with a similar procedure in both the…

This article examines first-birth timing among Mexican women in the United States over two birth cohorts. Currently, Mexican women are one of a small group that maintains above-replacement fertility in the United States, contributing to both Mexican population growth and overall national population growth. Yet, the fertility timing of Mexican…

Background: Breast cancer (BC), the most common cancer diagnosed in women in the United States, is a heterogeneous disease in which age-specific incidence rates (ASIRs) differ by race and mortality rates are higher in blacks than whites. Goals: (i) understand the reasons for the black-to-white ethnic crossover in the ASIRs; (ii) formulate a…

Using data from more than 2,000 community college science, technology, engineering, and mathematics (STEM) majors in the National Postsecondary Student Aid Study, this research investigates how ethnicity, gender, non-traditional student risk factors, academic preparation, socio-economic status, and English-as-second-language/citizenship status…

This exploratory study was designed to address how multiple factors drawn from varying focal models and ecological levels of influence might operate relative to each other to predict partner aggression, using data from 453 representatively sampled couples. The resulting cross-validated models predicted approximately 50% of the variance in men's…

This dissertation is a study of factors that contribute to dropout from distance learning classes in the Kentucky Community and Technical College System (KCTCS). It is divided into five chapters. Chapter One gives a history of distance learning through in KCTCS. It includes the background of the study, statement of the problem, purpose of the…

This article addresses whether students' achievement motivation changes over time, the relationship between changes in motivation and changes in educational attainment, and the between-school differences in these changes and their interrelationships. Also gender differences were studied. Multivariate multilevel latent growth curve analysis was…

The aim of this study was to investigate forces that affect the timing of women's exit from violent relationships with men. Abused women were recruited from posters in the community and battered women's shelters, interviewed, and followed up for 10 years. Data for this study are based on 100 women and were analyzed using event history analysis.…

Data from the Third International Mathematics and Science Study carried out in 1999 and canonical correlation analysis were used to investigate the effects of school inputs, environmental inputs and gender influence in the production of a joint educational production function in mathematics and science subjects for eighth grade students in…

The focus of this study was to identify factors that differentiate women drug abusers who had experienced suicidal ideation from those who did not. Face-to-face interviews were conducted with 221 cocaine-using women in Atlanta, GA, 88 (39.8%) of whom reported thinking about committing suicide at least once during the 90 days prior to interview and…

The outcomes and implementation of career academy programs in California were examined in a study of one school district's efforts to implement a uniform career academy model in 1990-1996. A cohort of approximately 10,000 students who were sophomores in the district's comprehensive high schools between 1990 and 1993 were followed through high…