The Trucking Retention and Academic Integration by Learning Style (TRAILS) research project at St. Louis University, which is designed to incorporate information on learning style in ongoing enrollment research and improve campus retention, is described. Learning style and the Tinto Model of student attrition are discussed, along with the personality theory of Carl Jung which serves as the conceptual foundation for the Myers-Briggs Type Indicator (MBTI) personality assessment. The TRAILS project positions educators to use the MBTI both in institutional studies and in campus programs. Most undergraduate students complete the MBTI as part of the housing application process or the freshman orientation program. Preliminary TRAILS data are presented pertaining to using the MBTI to describe academic populations, the relationship of the MBTI and measures of academic aptitude, the relationship of the MBTI and academic achievement, and using the MBTI to understand persistence patterns. It is suggested that certain personality characteristics affect student performance in many ways. The project attempts to meld these pieces in a comprehensive enrollment research scheme. Preliminary data suggest there are no differences between types of learners in upper-class academic achievement in the heart of their chosen curriculum. Also, if certain types of learners tend to score lower on aptitude tests then others, the trend of declining board scores takes on new meaning. Tables are included. Contains 15 references. (SM)