Differences Between Persons Responding and Not Responding to a Mailed Questionnaire

Marked differences exist between respondents and non-respondents to a mailed questionnaire. Higher intelligence scores and scholarship, loyalty or ties to the questionnaire sponsor, and a rural background, seem to be positively associated with the tendency to respond. Knowledge of the probable tendencies of bias in response to mailed questionnaires should enable the investigator to evaluate his returns and to phrase his questions and his appeal for response in a more effective manner.