The objective of this research, which is being conducted at the U.S. Naval Academy, is the development of personality measures to supplement the more scholastically oriented aptitude tests used in the selection of Naval Officers. The first year's work, recently completed, was concerned with a study of associates' and officers' ratings of midshipmen on "aptitude for service," or leadership potential. Intercorrelations were computed among aptitude for service ratings for three summer cruises and two academic periods, standings in academic courses, and scholastic aptitude test scores, using 633 members of the class of 1951. Results indicated that the aptitude ratings were quite clearly differentiated from academic standing, and from verbal, mathematical, and spatial ability. Considerable stability was found in the ratings from one marking period to another, except for the cruise ratings. A more detailed analysis of the ratings given and received by about 200 midshipmen from the larger group indicated that the midshipmen composite ratings were highly reliable. On the basis of the first year's work, it was felt that the aptitude ratings represented a suitable first criterion, and hence it was considered advisable and worth-while to proceed with the development and initial validation of personality measures to predict this criterion. This constitutes the objective of the second phase of the investigation which was recently initiated. Work is underway on the development of personality tests deemed to be most appropriate or promising in the light of what has been learned about the aptitude ratings during the first phase of the research.