Abstract
Returns and findings from three strategies of data collection are compared. Each strategy contains personal interviews, telephone interviews, and mail questionnaires in different combinations—one mainly personal, one mainly telephone, and one mainly mail. All three strategies are based on area probability samples of households in Alameda County, California. The test was made on two separate studies, with identical questionnaires used in all strategies within each study. The responses from the three strategies were found to be highly comparable. Rate of return and rate of completeness of questionnaires were high for all three; substantive findings were virtually interchangeable; and there was little difference in validity. The only important difference was cost per interview which varied considerably by strategy.