Technical annex

This technical annex outlines how the indices of professionalism are constructed, and contains additional information on their distribution. The approach to scale construction in this study differs from that used by the Teaching and Learning International Survey (TALIS) for complex scales, such as their scales for job satisfaction and teacher efficacy, which weigh factors differently based on their contribution to an underlying latent variable. In this report, additive scales are created based on implementation of best practices, rather than complex scales based on latent variables. Following recommendations of the TALIS 2013 Technical Report (OECD, 2014b), similar scales are created using confirmatory factor analysis and test for overall fit and scalar invariance. In most cases, the scales exhibit a relatively good fit overall cross-nationally, but are not scalar invariant across all countries. We also find that additive component scales are very highly correlated to factor scales (~0.90+), while also having the added advantages of comparability. As such, we made the decision to work with the additive composite indices because they are more intuitive, comparable and have better distributions for subsequent analyses.