Variables that influence growth and change in educational outcomes in the last 2 years of high school were studied using data from the High School and Beyond (HSB) study. The HSB study provided a database of thousands of variables for about 30 students from each of 1,000 randomly selected high schools in the United States in their sophomore and senior years and 2 years after graduation. This research summary briefly reviews studies on: (1) effects of public, Catholic single-sex, and Catholic coeducational high schools on achievement, affect, and behaviors; (2) effects of attending single-sex and coeducational high schools on achievement, attitudes, behaviors, and sex differences; (3) sex differences in the development of mathematics and verbal self-concepts; (4) failure of high-ability schools to deliver academic benefits; (5) influence of internal and external frames of reference on formation of mathematics and English self-concepts; (6) effects of employment during high school; (7) effects of extracurricular activities; (8) effects of participation in sports; and (9) changes in achievement, attitudes, and behavior in the last 2 years of high school for students from different family structures. Methodological implications from these studies are discussed. Three tables and 5 figures present data from the various studies, and 15 references are included. (SLD)