Potential Selective Responding in a Parent Questionnaire Study of Post-Institutionalized Children.

Selective responding bias, though under-researched, is of particular concern in the study of post-institutionalized children because many studies rely on mailed questionnaires and response rates are often low. The current study addresses the impact of selective responding in a single wave of data collection and in a multi-wave study. Participants were 121 parents from a larger four-wave study of post-institutionalized children, identified as Never Responders, Previous Responders (but not to the current wave), or Wave 4 Responders. Parents were telephoned and asked about their adopted child's family, school, peer, and behavioral adjustment. The children (47% male) ranged in age from 2 to 20 years (M = 10.79, SD = 4.59) and had been adopted between 5 and 54 months of age (M = 15.49, SD = 9.94). There were no differences in parent ratings of adjustment for a single wave of data collection; however, participants who never responded reported poorer family and peer adjustment than those who had responded to at least one wave of data collection. Within a single wave of data collection, there was no evidence that selective responding contributes much bias. Over a multi-wave study, however, results may under-represent adjustment difficulties, especially with family and friends.