Studies conducted by the United States Military Academy and Air Force Academy showed that many cadets who had attended preparatory schools which prepared high school graduates for college admission performed below what had been predicted by their scores on college entrance examinations. Based on these findings, about 1,200 students from 10 preparatory schools participated in a study to determine the effect of preparatory school test coaching on college entrance examination scores and subsequent performance in college. Scores on the September, 1962 and March, 1963 Scholastic Aptitude Test (SAT) and College Board (CEEB) achievement tests in mathematics and English composition were compared. Scores were correlated with five background variables: intelligence index, number of secondary schools attended, number of mathematics and English courses, and high school rank. Both SAT and achievement test scores increased, with CEEB scores showing the greater increase. Both SAT verbal and mathematics test scores increased significantly beyond what had been considered typical for a senior high school year. Also, cadets in the military academies performed significantly poorer than was predicted by CEEB scores, as indicated by an adjusted correlation of .35. Implications of the study are discussed, and statistical analyses of aspects of the study are appended. (CP)