Parental knowledge was assessed in the Home Environment section of the SSAGA-IV (4 items; “how many of your friends do you parent figures know?” “my parent figures know about my plans,” “my parent figures have a pretty good idea of my interests, activities, and whereabouts” and “my parent figures know where I am and who I am with when I am not at home”). Parental knowledge items were rated on a four-point ordinal scale: “always” (4), “usually” (3), “sometimes” (2) and “rarely” (1). School substance use also measured from the Home Environment section of the SSAGA-IV and was the composite of responses to four items pertaining to the perceived prevalence of cigarette smoking, alcohol use, marijuana use, and other illicit drug use among the “kids you go to school with.” These items were virtually analogous to the close friend substance use variables in that participants responded to each question on a four-point scale: “none of them” (1), a few of them (2), most of them (3), and “all of them” (4). If participants were over the age of 18, they
