Application of Rasch Analysis in Measuring Teacher Collegial Supervisory Instrument's Reliability and Validity

The concept of collegial supervision (CS) is defined as collaborative work beyond their professional sphere of relationships often offered by educators through feedback and sharing platform. However, there is still lack of studies and instruments that evaluated the CS practice within Malaysian context. In measuring the suitability of CS practice in secondary schools in Malaysia, a questionnaire with 26 self-developed items that represent five sub-dimensions/constructs namely, collegial relations, teacher's province, teacher growth, teacher collaboration, and reflective inquiry was developed from series of interviews with secondary teachers. The major aim of this paper is to validate and examined the psychometric elements through the application of Rasch analysis in measuring items'-person reliability, principal component analysis, items - person distribution, fit and dimensionality analyses. The analysis was performed based on feedback of 357 teachers from secondary teachers. Findings revealed on high values on person-items reliability, and the items' difficulty are significantly aligned or matched with teachers' ability. Also, principal component analysis revealed an acceptable value of raw variance explained, and that most teachers agreed with most of the items through structure measurement on the items' validity. Thus, it is concluding on the internal consistencies of the items within Malaysian CS which later contributed to the CS items for Malaysian secondary schools.