This study, part of the National Study of Student Learning, sought to determine the extent to which college students' development of internal locus of attribution for academic success during the first year of college was influenced by institutional characteristics, students' academic experiences, and their social/non-academic experiences. The sample was 2,392 first-year students attending 23 diverse two- and four-year institutions located in 16 states throughout the county. Controlling for precollege internal attribution, academic ability, and other potentially confounding influences, a number of variables had significant positive effects on end-of-first-year internal attribution. These included: attending a two-year (versus four-year) college, level of exposure to postsecondary education, work responsibilities, the extent of course organization, instructional clarity, instructor support in the teaching received, and participation in intercollegiate athletics. Additional analysis indicated that many of the effects on internal attribution were conditional rather than general, differing in magnitude for different kinds of students. Four tables of data present the details of the study. (Contains 61 references.) (Author/JB)