on parameter estimates. Frequency of drinking alcohol was also measured with a computerized questionnaire (“During the past 12 months, about how many times did you drink alcohol?”) at age 11 and 14 and the SAM (“In the past 12 months, how often on average have you drunk any alcohol (had any alcohol to drink)?”) at later ages. Participants responded on a 10-point scale that ranged from “Less than once a year” to “3 or more times a day.” There was considerably less skew and a much smaller range of responses for the measure of drinking frequency, and values thus were not log-transformed.
