Segments then were divided into clusters of approximately four to eight housing units, and all occupied housing units were included in the NLAES. Within each household, one randomly selected respondent, 18 years of age or older, was selected to participate in the survey. Oversampling of young adults, 18–29 years of age, was accomplished at this stage of the sample selection to include a greater representation of this heavy drinking population subgroup. This subgroup of young adults was sampled at a ratio of 2.25 percent to 1.00.
