The frequency and amount of peer alcohol use was assessed by scales from youth reports (Youth Interview; Describing Friends Questionnaire). Substantial associations have been found between perceived and actual peer use (Wilks et al., 1989). The scale items assessed alcohol use-related behaviors such as getting drunk, selling or giving alcohol to peers, and general frequency of use. As shown in Table 1, the correlation between the two Grade 6 Peer Alcohol Use indicators was .46. Although not used in the current study as they were only available at limited grades, peer reports of their own alcohol use were available at Grades 8, 10, and 12. Correlations between youth reports of peer use and peer self-reports were .42, .44, and .37, respectively (all p < .001), indicating reasonable validity of youth report of peer alcohol use. Note that peer reports were only for their own alcohol use, whereas the youth reports cover all their peers.
