According to a survey report of the Student Guidance Center at the Seoul National University, approximately thirty percent of the freshmen expressed the desire to be transferred to other departments. It was further reported that more than forty percent of them list the unsuitability of their academic departments to their interests and aptitudes as the reason for their desire to transfer. The present investigation of the structure of aptitudes should provide basic information necessary for effective educational and vocational guidance for the students and for policy making on the part of the university administration. This research purports to develop principles and strategies for the selection, placement, and guidance of freshmen. Specifically, the major purposes are, first, to examine the validity of aptitude tests for the selection of freshmen and second, to identify the relationships between the aptitude structures and the placement of freshmen. In addition, the study has the corollary purpose of determining the effectiveness of the Differential Aptitude Test. (Author/BW)