Hilbert, S., Küchenhoff, H., Sarubin, N., Nakagawa, T. T., & Bühner, M.
The influence of the response format in a personality questionnaire: An analysis of a dichotomous, a Likert-type, and a visual analogue scale
In the present study, 866 participants completed a questionnaire on the personality facet “dutifulness.” A dichotomous (DS), a 5-point Likert-type (LTS), and a 100-mm visual analogue scale (VAS) were analyzed regarding their effects on psychometric properties in a repeated measures design. Concerning estimates of reliability, it was shown that Cronbach’s alpha increased with the number of response alternatives of the scales, while McDonald’s omega and validity coefficients remained steady. It is argued that, given the τ-congeneric measurement model of the present study, omega provides the more adequate estimate of internal consistency. Generalized linear regression analyses indicated that the participants judged the intervals between varying levels of dutifulness on the VAS differently from the other two scales. It is concluded that the choice of response format should not be exclusively based on desired psychometric properties but rather on practical considerations.
Testing, Psychometrics, Methodology in Applied Psychology, 2016, Vol. 23, pp. 3-24, DOI: 10.4473/TPM23.1.1Back