Modellierung von Lehrerkompetenzen

This contribution will investigate both the subject-specific and the didactic competencies of trainee teachers for lower secondary education in mathematics on the basis of the study “Mathematics Teaching in the 21st Century (MT21)”, which compares criteria-based samples from Germany, Bulgaria, South Korea, Taiwan, Mexico and the USA. In order to analyze their strengths and weaknesses more precisely, the paper considers both traditional IRT-scaling of competencies, which involves a simple loading of test performance in mathematics and didactics of mathematics, and an alternative. Under the assumption that solving items concerning didactics of mathematics requires competencies in didactics of mathematics and mathematics itself, a double-barreled approach was used in the alternative. In a further elaboration of this model, knowledge of arithmetic, algebra, functions, geometry and stochastic was used as a set of further explanatory factors for solving the items. This third model, which presumes a hierarchical structure of teaching competencies, displays the best data fit. Only this model reflects the specialisms and focal points of the education and training systems in the countries participating in MT21 concerning the relative learning opportunities in mathematics and didactics of mathematics and concerning the five subject areas in the field of mathematics.