Handbook of Web Surveys. Jelke Bethlehem
However it has to be advised that mobile phone numbers are not listed in directories in many countries. Thus, a problem arises.
Example 1.2 is about the first telephone survey in the Netherlands.
EXAMPLE 1.2 The first telephone survey in the Netherlands
The first telephone survey took place in the Netherlands on June 11, 1946. See NIPO (1946) for a detailed description. An interview to a few hundred owners of telephones in Amsterdam asked a few questions about listening to the radio. The call to the people was between 20:00 and 21:30 hours on a Tuesday night. Some results are in Table 1.1.
Table 1.1 The first telephone survey in the Netherlands
| Are you listening to the radio at this moment? | Percentage |
|---|---|
| Was listening | 24 |
| Was not listening | 38 |
| Line busy | 5 |
| No answer | 31 |
| Did not have a radio | 2 |
If people declared they were listening to the radio, the program they were listening to was asked. It turned out that 85% was listening the “Bonte Dinsdagavondtrein,” a very famous radio show at that time.
Telephone interviewing has some limitations. Interviews cannot last too long, and no written answer is possible. Obviously, no show cards are used; lists are read loud (by the interviewers).
This implies a possible recency effect in the answers. Another problem may be the lack of a proper sampling frame. Telephone directories may suffer from severe under‐coverage because many people do not want their phone number is in the directory. Another new development is that increasingly people replace their landline phone by a mobile phone. This fact increases under‐coverage in the telephone directories. For example, according to Cobben and Bethlehem (2005), only between 60% and 70% of the Dutch population had at that time a telephone dictionary.
A way to avoid the under‐coverage problems of telephone directories is to apply random digit dialing (RDD) to generate random phone numbers. A computer algorithm computes valid random telephone numbers. Such an algorithm is able to generate both listed and unlisted numbers. Thus, there is complete coverage. An example of an algorithm used in the United Kingdom is to take a number from a directory and replace its last digit by a random digit. RDD also has drawbacks. In some country it is not clear what an unanswered number means. It can mean that the number is not in use. This is a case of over‐coverage. No follow‐up is needed. It can also mean that someone simply does not answer the phone, which is a case of nonresponse, which has to be followed up. Another drawback of RDD is that there is no information at all about nonrespondents. This makes correction for nonresponse very difficult (Bethlehem, Cobben, and Schouten (2011), see also Chapter 12).
The choice of the mode of data collection is not any easy one. It is usually a compromise between quality and costs. In large countries (like the United States) or sparsely populated countries (like Sweden), it is almost impossible to collect survey data by means of face‐to‐face interviewing. It requires so many interviewers that have to do so much traveling that the costs would be very high. Therefore, it is not surprising that telephone interviewing emerged here as a major data collection mode. In a very small and densely populated country, like the Netherlands, face‐to‐face interviewing is much more attractive. Coverage problems of telephone directories and low response rates also play a role in the choice for face‐to‐face interviewing. More about data collection issues is in Couper et al. (1998).
1.2.3 THE ERA OF COMPUTER‐ASSISTED INTERVIEWING
Collecting survey data can be a costly and time‐consuming process, particularly if high‐quality data are required, the sample is large, and the questionnaire is long and complex. Another problem of traditional data collection is that the completed paper questionnaire forms may contain many errors. Substantial resources must therefore be devoted to cleaning the data. Extensive data editing is required to obtain data of acceptable quality.
Rapid developments in information technology since the 1970s have made it possible to reduce these problems. By introducing microcomputers for data collection, important innovation in surveys took place. A computer program for asking questions and recording the answers replaced the paper questionnaire.
The computer took control of the interviewing process, and it checked answers to the questions. Thus, computer‐assisted interviewing (CAI) emerged.
CAI comes in different modes of data collection. The first mode of data collection that emerged was computer‐assisted telephone interviewing (CATI). Couper and Nicholls (1998) describe its development in the United States in the early 1970s. The first nationwide telephone facility for surveys was established in 1966. The idea at that time was not implementation of CAI but simplifying sample management. The initial systems evolved in subsequent years into full featured CATI systems. Particularly in the United States, there was a rapid growth of the use of these systems. CATI systems were little used in Europe until the early 1980s.
Interviewers in a CATI survey operate a computer running interview software. When instructed to do so by the software, they attempt to contact a selected person by telephone. If this is successful and the person is willing to participate in the survey, the interviewer starts the interviewing program. The first question appears on the screen. If correctly answered, the software proceeds to the next question on the route through the questionnaire.
Call management is an important component of the CATI systems. Its main function is to offer the right telephone number at the right moment to the right interviewer. This is particularly important in cases in which the interviewer has made an appointment with a respondent for a specific time and date. Such a call management system also has facilities to deal with special situations like a busy number (try again after a short while) or no answer (try again later). This all helps to increase the response rate. More about the use of CATI in the United States is in Nicholls and Groves (1986).
Small portable computers came on the market in the 1980s. This made it possible for the interviewers to take computers with them to the respondents. This is the computer‐assisted form of face‐to‐face interviewing, called computer‐assisted personal interviewing (CAPI). After interviewers have obtained cooperation of the respondents, they start the interviewing program. Questions display is one at a time. Only after the entering of the answer, the next question appeared on the screen.
At first, it was not completely clear whether this mode of data collection could use the computer. There were issues like the weight and size of the computer, the readability of the screen, battery capacity, and the size of keys on the keyboard. Experiments showed that CAPI was feasible. It became clear that CAI for data collection has three major advantages:
It simplifies the work of interviewers. They do not have to pay attention any more to choosing the correct route through the questionnaire. The computer determines the next question to ask. Interviewers can concentrate more on asking questions and helping respondents giving the proper answers.
It improves the quality of the collected data. Answers checking is by the software during the interview. Correction of the detected errors is automatic. The respondent is there to provide the proper information. This