The two dependent variables, intentions to use alcohol and cigarettes, were not normally distributed. Therefore, a log transformation was performed on the intentions to use alcohol variable (skewness = 1.01 and kurtosis = −0.39 for transformed variable) and a reciprocal transformation was performed on the intentions to use cigarettes variable (skewness = 2.02 and kurtosis = 2.78 for transformed variable). Chauvenet’s criterion (Taylor, 1997) suggested the existence of one outlying observation with respect to substance use intentions, so this participant was removed from subsequent analyses. A small number of adolescents reported having used alcohol (4.15%) or cigarettes (2.33%), and these observations were removed to examine intentions to initiate use. To eliminate non-essential multicollinearity first-order terms were standardized before forming the cross-product interaction terms (Aiken & West, 1991).
