The purpose of this study was to apply the tenets of social exchange theory in developing cover letters for mailed surveys. A survey questionnaire designed to measure teachers' attitudes toward tests was mailed to 1200 Kansas teachers. Cover letters were written to create variation in perceived cost (time needed to complete the questionnaire) and type of reward offered (egotistic, social utility, help the sponsor). Two questionnaire format sizes were used, one half as large as the other (conventional) size. Three forms of time cues were combined with each of the reward cues. Finally, all combinations of cost and reward conditions were included and mailed with a large format size and small format size of the survey questionnaire. The results suggest that the reward condition had no substantial effect on the return rate. The time and format conditions both produced an effect. Contradicting the theory, the lowest return rate occurred for the shorter time condition and the larger format size. (BW)