Why is the survey conducted in grades 5, 7, 9, and 11?
It is important that schools collect grade-level data (rather than use a general high-school sample) because drug use and other risk behaviors increase or change with age. Schools need to understand developmental differences in order to implement better programs that target each age group. Generally surveys target every other grade to help reduce the costs and disruptions involved and also provide convenient benchmarks. In California, where the HKS is mandated, it also assures that comparable data are collected by all HKS participants.
