Research findings on identification of factors associated with increasing response rates to mailed questionnaires are presented. Several tactics which have been used to effect a greater response rate are presented and explained. Physical factors, such as typed correspondence, have been shown to yield higher response rates than duplicated correspondence. Pre-questionnaire contact, such as a telephone call to inform subjects that they will be receiving a questionnaire, is effective. Use of a personalized cover letter has proven to be an essential and effective response-soliciting method. Monetary inducements initiate increases in response rates as do mailing procedures, such as using stamps on reply envelopes. Follow-up procedures are effective in increasing response rate. A compilation of additional suggestions offered by the authors cited in the literature review is included. (DWH)