Reliability and completion speed in online questionnaires under consideration of personality

- Demographics and impulsiveness were tested for an effect on completion time.
- Bayesian tests allowed for quantification of evidence against an effect.
- Only age had a direct impact on the completion speed.
- Evidences against an effect of personality on speed in questionnaire completion.

While self-administered web questionnaires are increasingly used in psychological and market research, the quality of collected data has to be continuously inspected. Two key questions were investigated in this paper: Does the overall completion speed in an online self-report questionnaire influence the reliability of personality scales? We assessed the Five-Factor Model of Personality (using NEO-FFI) and Impulsiveness (using BIS-11). Second, we asked if Impulsiveness predicts the overall completion speed.In total, 532 participants (436 females, 96 males; mean age = 25.57 years) engaged in an online study to answer these questions. Replicating previous findings, no difference in the reliabilities was found for fast or slow respondents. While underlining the effect of Age on the completion speed, our data indicated evidence against our hypothesis of an influence of Impulsiveness on completion time using a Bayesian approach. Similar results could be observed using classical inferential methods. Of note, no effect could be observed for the Five-Factor Model of Personality and completion time either. Therefore, personality traits are not associated with individual differences in completion time in our investigated sample. We discuss our findings in a broader context of survey research and give a perspective for future research opportunities.