Overall messages on response styles and scale use
The nature of subjective measures means that we can never really know whether one respondent’s 8 out of 10 corresponds to the exact same mental state as another respondent’s 8 out of 10. Individual differences in response styles and scale use may inevitably add some noise to self-report data - although the clear evidence for the validity of subjective well-being measures indicates that this noise is not a major threat to the usefulness of the data. The accuracy of comparisons between two groups of respondents may, however, be limited if it can be demonstrated that those two groups exhibit systematically different patterns of response styles or scale use.
Several empirical issues limit our ability to separate responses styles and differences in scale use from genuine real-score differences in the subject of interest. Applying ex post corrections, such as for the average number of agreements across the survey, prior to analysis might eliminate interesting sources of variation, introduce non-independence in the data and reduce interpretability. More sophisticated statistical techniques based on item response theory present a promising way forward in terms of identifying cultural differences in scale (i.e. number) use, but they do not eliminate the influence of several other types of response bias, such as acquiescence and social desirability (Oishi, 2006). We are also far from having reached firm conclusions in terms of what cultural differences in scale use mean for each country and how we should measure or correct for this in making international comparisons.
Given that individuals are assumed to be more likely to rely on response biases and heuristics when they are confused by questions, less motivated, more fatigued and more burdened, the best way to minimise these issues is likely to be through adopting sound survey design principles: avoiding items that are difficult to understand or repetitive or that look too similar; using short and engaging questions that are easy to answer; and keeping respondents interested and motivated. Other sections of this chapter have discussed these issues in more detail. Of course, if the source of a response style is largely cultural, rather than related to the demands of the survey, it will be more difficult to address through question and survey design itself - and the methods for management include both collecting panel data and potentially applying post hoc adjustments (see Chapter 4).
Where a strong risk of fatigue-related response styles is anticipated, the length of the survey and the sequencing of questions should also be carefully considered - perhaps with more cognitively challenging questions timed to coincide with points in the survey where respondent motivation is likely to be highest. Of course, this needs to be balanced against recommendations from the previous section on question order (and in particular, the need to avoid contamination between subjective well-being and other socially sensitive survey items). As question order effects can sometimes be considerable, minimising these should be considered the first priority.
Although there is some evidence that response styles can influence responses to evaluative and affective questions, there is little reason to believe that subjective well-being measures are uniquely susceptible. In general, the effect of response styles on evaluative and affective responses appear to be small, and perhaps of most significance when examining cultural differences in reporting. Less is known about eudaimonic scales, however, and some scale design features may make them more vulnerable to response styles. In particular, there are a priori grounds to expect that questions with agree-disagree response formats might be more likely to elicit stronger acquiescence tendencies.