Measuring the Variability of Personality Traits With Interval Responses: Psychometric Properties of the Dual-Range Slider Response Format

Abstract

The measurement of variability in persons’ behaviors and experiences using ecological momentary assessment is time-intensive and costly. We propose to use interval responses (i.e., the dual-range slider response format, DRS) as a simple and efficient alternative. Respondents indicate variability in their behavior in a retrospective rating by providing a lower and an upper bound on a continuous, bounded scale. We investigate the psychometric properties of this response format as a prerequisite for further validation. First, we assess the test-retest reliability of factor-score estimates for the width of DRS intervals. Second, we test whether factor-score estimates of the visual analog scale (VAS) and the location of DRS intervals show high convergent validity. Third, we investigate whether factor-score estimates for the DRS are uncorrelated between different personality scales. We present a longitudinal multi-trait multi-method study using two personality scales (Extraversion, Conscientiousness) and two response formats (VAS, DRS) at two measurement occasions for which we estimate factor-score correlations in a joint item response theory model. The test-retest reliability of the width of DRS intervals was high (r ≥ .73). Also, convergent validity between location scores of VAS and DRS was high (r ≥ .88). Conversely, discriminant validity of the width of DRS intervals between Extraversion and Conscientiousness was poor (r ≥ .94). In conclusion, the DRS seems to be a reliable response format that could be used to measure the central tendency of a trait equivalently to the VAS. However, it might not be well suited for measuring intra-individual variability in personality traits.