Soniawati, N.I. et al. 2026. Optimal number of response categories for a Likert-type questionnaire: A simulation study within the frameworks of Classical Test and Item Response Theory. REID (Research and Evaluation in Education). 12, 1 (Jul. 2026), 1–25. DOI:https://doi.org/10.21831/reid.v12i1.95846.