The face validity of measures is important because it can affect both respondent motivation and the acceptability of resulting data to potential users of that data. The face validity of subjective well-being is relatively straight-forward to establish. The standard questions used have a clear intuitive relationship to the concept being measured. It is not a great stretch, for example, to suggest that asking a person whether they experienced sadness during the previous day is a plausible way to find out whether they felt sad during that day. Although it is relatively unusual to ask respondents about face validity directly, there are a number of pieces of evidence that suggest that respondents find questions on subjective well-being easy to understand. For example, the time it takes respondents to reply to questions on subjective well-being is low, with median response times well under thirty seconds for single item questions (ONS, 2011).This indicates that respondents do not generally find such measures conceptually difficult to understand. Cognitive testing by the ONS also supports the view that respondents do not generally find subjective questions difficult or upsetting to answer, nor does the inclusion of such questions negatively impact the response rates to subsequent questions or to the survey as a whole (ONS, 2011; ONS, 2012). Measures of subjective well-being also have low item-specific non-response rates (Rassler and Riphahn, 2006), suggesting that respondents do not find these types of question difficult to answer.
In a large analysis by Smith (2013) covering three datasets (the Gallup World Poll, the European Values Survey and the World Values Survey) and over 400 000 observations, item-specific non-response rates for measures of life evaluation and affect were found to be similar to those for measures of educational attainment, marital status and labour force status. The acceptability of the subjective well-being measures, however, appeared to be higher than that of income, which is commonly collected as part of official statistics, and had an item-specific non-response rate of between 10 and 100 times higher than subjective well-being measures, depending on the country. The results also held when item-specific non-response rates were broken down by cause (into “don’t know” and “refused to answer”) and regardless of whether the measure tested was evaluative (life satisfaction or the Cantril Ladder) or affective.