The effect of prenotification techniques on refusal rate in telephone surveys

Response rate is of great importance for the representativeness of a study. When it is low, there is a chance that response is selective, as the people who refuse may constitute a selective sample of the target population. Much research has already been done into the sociopsychological aspects affecting response, but so far little attention has been paid to the effect of different communicative approaches. In our study we examine the effects of a two-phased communication plan on refusal rate in telephone surveys. In real-life experiments, we investigated the effects of two prenotification techniques: sending advance letters and leaving a message on an answeringmachine or voice mail. Sending advance letters led to a statistically significant decrease in refusals by 25%, but leaving a message on answering machines or voice mail led to no statistically significant decrease in refusals. The results are interpreted in the light of Compliance Theory and Elaboration Likelihood Theory. Possible consequences for research bureaus that conduct telephone surveys are discussed.