A factor analytic comparison of dichotomous and polytomous response categories

M.Comm.It was investigated whether dichotomous (2-point) or polytomous (5-point) rating scales have superior functioning on the personality construct Soft-Heartedness for the South African Personality Inventory (SAPI). The optimal number of rating scale categories for a personality measure was explored. The participants comprised students of diverse racial and cultural backgrounds at a South African tertiary institution (N =708). Two alternate forms of a test measuring Soft-Heartedness were administered to two alternated groups (n1 = 344; n2 = 364). Either version of the test contained a 2-point and 5-point version. These two formats were then factor analysed and subjected to a tetrachoric/polychoric correlation analysis. They were also tested for reliability using the Cronbach Alpha coefficient and composite reliability coefficient. In addition, the coefficient of congruence was established. It was found that the 2-point scale has more functional psychometric properties than the 5-point scale regarding the factor structure and composite reliability. This was attributed to cultural, perceptual, linguistic, educational, and test-experience components