Young adults who had previously participated in a longitudinal survey of youth were sent a questionnaire. They were randomly assigned to receive a $20 prepayment, a $20 postpayment, or a $25 postpayment for participation in the latest survey. Those in the large incentive condition were 7...

This study provides new information on how passive and active consent methods work in practice. Based on results from two junior high schools, we found that (1) almost all parents received consent packages sent by regular first-class mail, but getting them to pay attention to the materials often...

This article describes a successful approach for tracking a highly mobile group of junior high school transferees and thereby minimizing attrition in a longitudinal study of adolescent behavior. Students were tracked through the home or the new school. When students were located through the...