Abstract
The first aim of this study is to test two assumptions of integer scoring (the assumption of ordered response categories, and the assumption of ordered thresholds). We tested these assumptions using a set of items extracted from the social boldness scale of the 16PF questionnaire that were presented with three different middle response categories: "Not sure", "In between" and "?". The second aim was to compare a 3-point response scale with a dichotomous response scale in terms of the information function and correlations with external criteria. The sample was composed of 816 undergraduate students. The results obtained showed that both assumptions were met only when the middle response category was "In between". The results also revealed that a 3-point response scale including "In between" provided more information than a dichotomous response scale. Both scales showed similar correlations with the considered external criteria.
