... Attention centered on interactive and causal links between student background, educational and institutional commitment, and academic and social integration. These studies gave rise to validation analyses that focused on identifying constructs with the best set of complementary variables to maximize model explanation (Berger and Braxton, 1998;Braxton, Sullivan, and Johnson, 1997;Cabrera, Castaneda, Nora, and Hengstler, 1992;Cabrera, Nora, and Castaneda, 1993), while others concentrated on the impact of specific factors on retention, such as assimilation courses (Hendel, 2001;Sidle and McReynolds, 1999), selected program major (St. John, Hu, Simmons, Carter, and Weber, 2004;Mau, 2003), admission status (Laden, Matranga, and Peltier, 1999), student ethnicity and gender (Grandy, 1998;Leppel, 2002), classroom-based learning experiences (Braxton, Milem, and Sullivan, 2000;Tinto, 1997), institutional support services (Lau, 2003), intention to leave (Okun, Benin, and Brandt-Williams, 1996), academic and social integration (Beil, Reisen, and Zea, 1999), and pre-collegiate academic preparation (Cambiano, Denny, and De Vore, 2000). ...