Effect on survey return rates of having a signed or unsigned postcard as the third-wave mailing

Abstract

This study assessed differences in response rates to a three-wave mail survey when signed or unsigned postcards were the third wave of the mailing (after two mailings of the questionnaire). A total of 259 signed postcards and 259 unsigned postcards were mailed as the third-wave mailing. There were 34 signed postcards and 30 unsigned postcards returned, a not significantly different distribution by chi-square test.