A multistage cluster sampling design was
employed to obtain a representative sample of
adolescents enrolled in public high schools as
part of the 1995 Massachusetts Youth Risk Behavior
Survey. At the first stage of sampling, 63
of 299 schools with 100 or more students in
grades 9 through 12 were randomly selected
with probability proportional to school size.
The overall school response rate was 94%; 59
of 63 schools agreed to participate. On average,
3 to 5 required classes (e.g., English, homeroom)
per school were randomly selected at
the second stage of sampling, yielding a total
of 5370 students, 4159 of whom completed
the survey