In the history of survey research, no other technical or procedural innovation, with the exception of the computer, has made as significant an impact on this type of data gathering as the telephone. A significant portion of (the increased use the telephone) can be attributed to the rising costs and declining response rates experienced by the face-to-face survey. The rise to prominence of survey by telephone is also the result of improved telephone technology, improved telephone research procedures, and then nearly complete accessibility of any population via the telephone.
A recent study analyzed indicated 250,000 telephone dialings between 8:00 am and 9:00 pm on week days with the following results:
34% of all calls not answered
2% line busy
20% line out of service
29% no eligible adult at home
10% reached an eligible person
15% of eligible persons refused to talk
8% of all calls resulted in a completed questionnaire
The two quotations above seem to be in opposition to each other, one suggests telephone communication is becoming dominant while the other indicates it is very hard to collect data the telephone. Both are correct. Previous data showed the widespread use of the telephone method even though there are problems involved. But there are problems in collecting data by any method; on average the advantages now seem to be with the telephone.
Some of the problems in using the telephone for interviewing have been suggested. Telephone interviews are not as versatile as personal interviews as it is difficult to handle over-the-telephone interviews that need visual aids; that are relatively unstructured or have questions that require long, descriptive answers or that call for observation of the respondents or their environment. Imaginative researchers, however, continues to find methods of overcoming these problems. If product samples are needed they may be mailed or delivered in advance. Audio aids may be found to replace visual aids.
While about 95 percent of all homes nationally have telephones it does not follow that all people can and will provide data over the phone. Many phone numbers are not listed, phones are out of services, lines are busy, and people are not at home. Nevertheless, ingenious researchers have found methods of coping with these difficulties.
Modern technology and organization have changed the nature of telephone surveys in a major way. Wide Area Telephone Service (WATS) offered by the Bell System makes it economically feasible to handle nationwide surveys from one location. Random Digit Dialing (RDD) makes it feasible to select probability samples of all telephones homes, including those homes with unlisted numbers. Cathode Ray Tubes (CRTs) and computer systems make it possible to have questionnaire programmed to appear on the tube (similar to a TV picture) in front of the interviewer in the sequence in which the questions are to be asked. Answers to questions except of discussion type responses can be recorded by the interviewer directly into the computer system, thus simplifying the tabulation problem.
Each of these major issues will be considered at greater length in the following discussion of the factors that determine which method of data collection can be used in a given situation.
Information Obtained: Several studies have collected data by different methods (telephone, mail, personal interview) and have generally concluded that the information obtained by the various methods tends to be comparable. Nevertheless, some variations should be noted.
Most people tend to respond more briefly to open questions a over the telephone and it is difficult to hold interest while the phone is ‘dead’ when the interviewers is recording answers. It is desirable therefore to limit the number of questions that may require lengthy answers and to eliminate gaps in the conversation perhaps by interviewers repeating answers while they are writing them down.