This report was prepared for the specialist who, well acquainted with the concepts and statistics of educational measurement, needs technical information about the Admissions Testing Program of the College Entrance Examination Board. It brings together the findings of a considerable number of studies of the Scholastic Aptitude Test (SAT) and the Achievement Tests. Three publications predated this book and they serve as a compendium of available information on the College Board Admissions Testing Program up to 1957 stressing proper test use and test interpretation for admissions and guidance. Recent manuals tend to be more interpretive than explicative. It is the aim of this book, however, to fill the information gap by providing the data needed for a comprehensive technical evaluation of the tests. In order to indicate the setting within which the program functions, a brief historical sketch, as well as administrative and psychometric considerations are briefly outlined. The scholastic Aptitude Tests and Achievement Tests are discussed and interpretive summary statistics for various subgroups of students are presented as are extensive validity studies of the admissions tests. Finally, the major findings of special studies that have been made in connection with the SAT and the Achievement Tests are summarized. (Author/CK)