Measurement of Latent Variables With Different Rating Scales: Testing Reliability and Measurement Equivalence by Varying the Verbalization and Number of Categories

Effects of rating scale forms on cross-sectional reliability and measurement equivalence were investigated. A randomized experimental design was implemented, varying category labels and number of categories. The parti-cipants were 800 students at two German universities. In contrast to pre-vious research, reliability assessment method was used, which relies on the congeneric measurement model. The experimental manipulation had dif-ferential effects on the reliability scores and measurement equivalence. Attitude strength seems to be a relevant moderator variable, which influ-ences measurement equivalence. Overall, the results show that measure-ment quality is influenced by rating scale forms. Results are discussed in terms of their implications for latent variables measurement