The general purpose of this project was to examine the process of becoming a scientist, from elementary school through four years of post-college work. Seven hundred male students in the Boston area, from 5 different grade levels (grades 5, 8, 11, 14, and 16), were studied for 5 years, thus covering a 16 year developmental span. Data collection included interviews of students and teachers, standardized achievement and aptitude tests, personality and interest inventories, questionnaires for students and parents, and two projective instruments. The term "Potential Scientist Pool" (PSP) was defined. The boys involved in this study were chosen from the PSP at all grade levels. Movement into or out of the PSP was determined during the 5 years of the study. The rationale behind this experimental design is discussed in detail. (Author/BB)