Of all the areas related to the validity of the Commonwealth Secondary Scholarship Examination (CSSE) tests, that of predictive validity seems to have been studied most intensively. Since the inception of the CSSE scholarship scheme, a series of studies which have either examined the predictive validity of certain aspects of the scholarships, or which have borne directly on that topic, have been reported. Investigations have been carried out on the predictive validity of the awards, of the CSSE total score, and of the individual CSSE test papers. These studies will be reviewed in this report. This investigation will be concerned with the ability of the CSSE tests to predict performance on some measures not previously used, as well as performance on some of the previously used measures of academic aptitude or academic success. In the process, some of the earlier work will be replicated. In addition, consideration will be given to the incremental effectiveness of the CSSE tests, or the degree to which they can improve the prediction of performance provided by other measures. The investigation will then be extended into an examination of the characteristics of those students who perform well on the CSSE tests, but perform poorly on a subsequent occasion (in the matriculation examinations), and vice versa. (Author/DEP)