Abstract—The study assessed the dimensionality of the Chemistry Teachers’ Effectiveness Scale (CTES) in Osun State, Nigeria secondary schools. Also, the study determined the extent to which CTES satisfies the unidimensionality assumption of the Item Response Theory model. It determined the extent to which the observed unidimensionality of CTES was confirmed when the scalability of the individual items and the overall scale was assessed. The study employed a survey research design. Thirty-five (35) Chemistry teachers who were rated by their Heads of Departments and Chemistry students made up the sample for the study. A multistage sampling procedure was employed for choosing the sample in two phases-: validation (conducted in Oyo State), and pilot testing (conducted in Osun State). A self-developed research instrument titled "Chemistry Teachers Effectiveness Scale (CTES)" was used for data collection. Items of the CTES were rated on a four-point Likert-type scale described under 1 = very poor, 2 = poor, 3 = moderate, and 4 = good. The Chemistry teachers’ effectiveness scale started with the initial version of 206 items, and was reduced to 96 items after validation. The 96-item second version of CTES was reduced to 62 items after pilot testing and reliability analysis (giving Cronbach Alpha coefficient of 0.92). A thorough and more robust statistical analysis was conducted on the 62-item third version of CTES. Mokken Scaling Analysis (MSA) was used to analyse the data via the Mokken package. Results showed that all the items of CTES have scalability coefficients within the 0.20 and 0.39 range and violated the Item Response Theory (IRT) unidimensionality assumption. The study concluded that items of the CTES are multi-dimensional.
Keywords: Chemistry Teachers Effectiveness Scale, dimensionality, Item Response Theory, Multidimensionality, Unidimensionality
Adamu, C. D. (2023). Dimensionality of chemistry teachers' effectiveness scale (CTES) in secondary schools in Osun state, Nigeria. International Journal of Studies in Psychology, 3(2), 77-81. https://doi.org/10.38140/ijspsy.v3i2.941.