THE RELATIONSHIP BETWEEN NUMBER OF RESPONSE CATEGORIES AND RELIABILITY OF LIKERT-TYPE QUESTIONNAIRES

The purpose of the study was to investigate the relationship between number of response categories employed and internal-consistency reliability of Likert-type questionnaires. Two questionnaires, each composed of items with high loadings on one factor, were scaled with 2, 3, 4, 5, 6, and 7 categories. The questionnaires were administered to graduate students in education and coefficient alpha reliabilities were computed both for random samples of items and for each total questionnaire. The results indicated that in situations where low total score variability is achieved with a small number of categories, reliability can be increased through increasing the number of categories employed. In situations where opinion is widely divided toward the content being measured, reliability appeared to be independent of the number of response categories.