This study provides preliminary evidence as to the validity of measures derived from the "Tests of Scientific Thinking" (TST). The TST and the Graduate Record Examinations (GRE) were compared with regard to their relationships to interests, self-appraisals, and accomplishments of students during their first year of graduate work in psychology. Criterion variables were obtained from a questionnaire mailed to students near the end of the spring academic semester. Difficulties in data analysis were created both by the item-sampling character of the experimental test data, and by a relatively small rate of return of questionnaires. It is possible to show, however, that the correlations do exhibit appreciable nonchance variance with regard to consistency across tests and across related questionnaire variables. The GRE tests were found to be more effective than the experimental instruments in predicting quality of the department attended, but the experimental tests were more effective in two other domains: self-appraisals of knowledge of psychology and skills in psychological activities; and professional accomplishments such as research, publications, and teaching. (Author/ROF)