Surveys can be carried out in a number of different modes. Because the mode of collection influences survey costs and respondent burden and can induce mode effects in responses, the choice of mode is an important decision when collecting data.The two modes most commonly used to collect information on subjective well-being are Computer-Assisted Telephone Interviewing (CATI), conducted by an interview over the telephone, and Computer-Assisted Personal Interviewing (CAPI), where the interviewer is personally present when recording the data. Computer-Assisted Self-Interview (CASI) surveys can occur in the presence of an interviewer, when the interviewer is on hand but the respondent enters their own data into a computer questionnaire, or without an interviewer present, such as when the respondent completes an Internet survey. For some purposes traditional chapter-based self-complete surveys are still likely to be relevant. Most time-use diaries, for example, are self-completed chapter diaries filled in by the respondent.
As outlined in Chapter 2, there is good evidence that the collection mode has a significant impact on responses to subjective well-being questions. In general, the use of CASI as a mode tends to produce lower positive self-reports than the use of CAPI, and this is assumed to be because interviewer-led approaches are more likely to prompt more socially desirable responding. CATI is viewed as the least reliable way to collect consistent subjective well-being data, because in these conditions the interviewer is unaware of whether the respondent is answering in a private setting or not, and it is more challenging for interviewers to build rapport with respondents.
As with other features of survey design, the choice of the survey mode will be influenced by a variety of factors, including resource constraints. However, the balance of evidence suggests that, where resources permit, CAPI is likely to produce the highest data quality. This is probably due in part to the rapport that interviewers can build in face-to-face situations. However, CAPI also provides the opportunity to use show cards, which CATI lacks. Show cards that include verbal labels for the scale end-points are particularly valuable in collecting information on subjective well-being where the meaning of the scale end-points changes between questions, as this can impose a significant cognitive burden on respondents (ONS, 2012).
In terms of data quality, CAPI with show cards should be considered best practice for collecting subjective well-being data. Where other modes are used it is important that data producers collect information to enable the impact of mode effects to be estimated. National statistical agencies, in particular, should consider experimentally testing the impact of the mode on responses to the core measures of subjective well-being and publishing the results along with any results from CATI or CASI11 surveys.