The Learning Outcomes Study, a 2-year investigation, evaluated four popular types of grouping arrangements for gifted students in grades 2 and 3 in 14 collaborative school districts in 10 states. The study compared within-class, pull-out, separate class, and special school instructional arrangements. Study participants (N=1000) included students who had either just entered gifted programs, were high ability students not in special programs, or were nongifted students. Analyses focused on assessments of achievement, attitudes toward learning processes, self-perception, intrinsic/extrinsic motivation, student activities, behavioral adjustment, and teacher ratings of learning, motivation, and creativity. In terms of achievement, gifted children attending special programs performed better than gifted peers not in programs. Students from the gifted comparison group, or in within-class or pull-out programs had higher perceptions of their scholastic abilities than did children in separate class or special school programs. No differences by program type or ethnic status were found for social acceptance. Also, no significant differences appeared either across groups or according to racial/ethnic status regarding internal versus external criteria for success/failure. Students in the separate class and special school programs scored the lowest on the "preference for challenge" scale, but had the highest levels of achievement in a traditionally more academic environment. Students in special schools had the highest scores regarding attitudes toward learning. Results suggest that no single program fully addresses all the psychological and emotional needs of students. Extensive appendices provide detailed methodological and analytical information on the study. Twenty-seven tables and five figures also detail study findings. Executive Summary is also published separately. (Contains approximately 140 references.) (DB)