Introduction: Methodological challenges and strategies in the TEDS-M study

This chapter provides an introduction to Part III of the book which highlights specific methodological challenges and strategies in the Teacher Education and Development Study in Mathematics (TEDS-M), a cross-national study of teacher education programs that prepare future primary and secondary mathematics teachers. The TEDS-M Technical Report (Tatto MT, The Teacher Education and Development Study in Mathematics (TEDS-M). Policy, practice, and readiness to teach primary and secondary mathematics in 17 countries: technical report. International Association for the Evaluation of Student Achievement, Amsterdam, 2013) provides the complete methodology and procedures. Chapters in this part discuss challenges with sampling, interpretation, and validation. The chapter on sampling introduces non-statisticians to the basic concepts of statistical sampling and its application in TEDS-M using examples and graphical illustrations. Instruments to capture the demographic and outcome variables of interest in TEDS-M did not exist, much less for use internationally, so TEDS-M researchers had to create, validate, and interpret appropriate measurements for the target populations. Importantly, the TEDS-M study, at the request of the participating countries, included assessments of knowledge, an approach that had not been attempted at the time in any country, much less at an international scale. The chapter on anchor points explains the development of a method to help interpret the assessment results. While the TEDS-M Technical Report includes information on overall instrument validation, the final two chapters in this Part III, look more closely at differential item functioning, and at the alignment of the teacher knowledge assessments to national expectations concerning mathematical knowledge for teaching using the United States case as an example.