| Abstract: | Recently, the leading position of telephone surveys as the majormode of data collection has been challenged. Telephone surveyssuffer from a growing nonresponse, partly due to the generalnonresponse trend for all surveys and partly due to changesin society and technology influencing contactability and willingnessto answer. One way to counteract the increasing nonresponseis the use of an advance letter. In mail and face-to-face surveys,advance letters have been proven effective. Based on the proveneffectiveness in face-to-face and mail surveys, survey handbooksadvise the use of advance letters in telephone surveys. Thisstudy reviews the evidence for this advice and presents a quantitativesummary of empirical studies on the effectiveness of advanceletters in raising the response rate for telephone surveys.The major conclusion is that advance letters are also an effectivetool in telephone surveys, with an average increase in responserate (RR1) from 58 percent (no letter) to 66 percent (advanceletter), and an average increase in cooperation rate (COOP1)from 64 percent (no letter) to 75 percent (advance letter). |
