Study time is one of the measurable and informative indexes of learning behavior. This paper studies the effect of college students’ study time on learning outcomes by classifying study time into three categories- time for attending classes (study time A), time for preparing for classes or reviewing previous classes (study time B), and time for spontaneous study other than class requirements (study time C). One of the major findings is that study time B and C increase learning outcomes significantly. Study time A does not have a significant effect in both fields of humanities/social sciences and natural sciences/engineering. By contrast in medicine/other health related fields, study time A has significant influences and they differ depending on the type of learning outcomes: it has a positive effect on acquiring special knowledge but negative effect on acquiring generic skills. These results suggest that it is important for college to encourage students to study more outside of classes in view of differences among fields of study.
