The Comparative Prediction Project intended to investigate the possibility of comparative prediction in school and college by means of pure-factor tests. This bulletin is the complete technical report on the high-school study. A battery, consisting of 13 "pure-factor" aptitude tests, 7 information (interest?) scores, and 10 personality factor scales, was given to beginning tenth graders in 49 Massachusetts high schools. The scores were validated against grades in the various academic and trade courses given during the tenth, eleventh, and twelfth grades. They were also validated against satisfaction with chosen curriculum. The results forecast that a test battery of this kind by itself would have only moderate value for differential and comparative prediction in practice, but, when used in conjunction with school grades and other information, it would make a substantial contribution. Better differential prediction obtained in the college-level study was recognized to have been brought about by the use of self-report interest scales. These could be used equally well at the high-school level. Previous project reports include RB-51-12, RB-53-16, RB-53-22, RB-54-07, RB-55-04, RB-55-06, RB-56-01, RB-59-10, RB-59-15, RB-61-07, and RM-61-13.