How were adolescents identified as eligible for special oversamples for the in-home interview?
An adolescent’s answer to a specific question or questions on the In-School Questionnaire determined his or her eligibility for inclusion in an oversample. For example, an adolescent who marked “Chinese” as his or her Asian or Pacific Islander background was eligible for the Chinese oversample. The genetic oversamples were identified in two ways. All adolescents who indicated they were twins were sampled with certainty. When an adolescent indicated at least one other household member in grades 7 through 12 with whom he or she did not share a biological mother and/or biological father, they were added to the pool of potential half-siblings and other, non-related adolescents. Full siblings were not oversampled.