MEETING THE CHALLENGE OF ANSWERING MACHINES

Answering machines have become one of the major challenges toobtaining high response rates in telephone surveys. This articlepresents some data that may be helpful in answering two questionsthat frequently arise: (1) What are the chances that additionalcalls to a household known to use an answering machine willresult in a completed interview? (2) When is the best time tocall, in order to minimize the chances of encountering an answeringmachine? The data used to analyze these questions are basedon the calling records of the 1990 California Disability Survey,a large random-digit dialing survey that generated about 330,000calls and completed interviews at over 24,000 house holds. Thislarge number of calls is interesting not only in absolute termsbut because of the high number of callbacks that they represent,designed to bring the response rate up over 80 percent. Therecords of calls analyzed here, consequently, can show convincinglywhat really happens when 10, 20, 30, or even more callbacksare attempted. Such opportunities are rare. Researchers cantake advantage of these results to generate more informed callingstrategies and consequently improve response rates in theirsurveys.