Comparison standards that people use when responding to survey questions, also called Frames of Reference (FoRs), can influence the validity of self-report responses. The effects of FoRs might be the stronger for items using vague quantifier (VQ) scales, which are particularly prominent in quality of life research, compared with numeric responses. This study aims to investigate the impact of FoRs on self-report measures by examining how imposing a specific FoR in survey questions affects (a) the response levels of VQ and numeric scales and (b) the relationship between VQs and a quantitative responses to the same question. A sample of 1,869 respondents rated their education, commute and sleep duration, medication use, and level of physical activity using both VQ and numeric formats. Participants were asked to compare themselves with the average US adult, with their friends who are about their age, or did not receive specific instructions regarding a reference for comparison. We found that FoR conditions did not influence the numeric responses. Among the VQ responses, only education attainment was affected by FoR. The association between the numeric responses and vague quantifiers was comparable across different FoR conditions. Our results showed that manipulating the use of interpersonal FoRs had limited effect on the responses, which suggests that at least some comparisons do not have a strong biasing effect on self-report measures. However, future research should confirm this finding for using other FoRs (e.g., historical or hypothetical comparisons) and other outcome measures.
Keywords: Frames of reference; comparison standards; self-report; survey research; vague quantifiers.