The entire incoming freshman class at a southwest university (N = 6,391) was recruited during summer orientation activities to participate in a study of risk behavior during the transition from high school through college. Participants (N = 4,832) were randomized to 3 conditions. Of the 3,046 randomized to the longitudinal condition upon which the current study focused, 2,245 (73.5%) participants who were unmarried and had never been enrolled in a 4-year university completed Assessment 1. Participation rates for the remaining assessments ranged from 96% (N = 2,150; Year 1) to 63% (N = 1,539; Year 4). Our focus on AO and delay required that participants have valid AO/AI data, resulting in the exclusion of 1,060 participants (743 did not complete the eighth assessment when AO/AI was assessed; 309 had not drank to intoxication by the final assessment; 8 were missing AO data or reported an AI > AO). Furthermore, only groups with sufficient sample sizes for meaningful analyses were included (Caucasian, Asian American, African–American, Latino, and multiethnic); 25 participants who were missing racial data or were from a group with
