Ko-WADiS: Evaluating the Development of Scientific Literacy in Teacher Education

The aim of this study was to evaluate the development of pre-service teachers' scientific reasoning competencies in three science disciplines: biology, chemistry, and physics. We constructed 123 multiple-choice items, using students’ conceptions to generate attractive response options. The test was applied to a longitudinal panel design with two waves of observation during the pre-service teachers' undergraduate studies and two additional waves during their postgraduate studies. To further optimize the instrument, we selected 63 of the initial 123 items. A multimatrix design with 21 items per booklet was used to limit individual testing time and effort to a reasonable level. Uni- and multidimensional IRT analyses show good reliability of the test. Validation studies provide evidence which supports our interpretation of the test scores as measures of scientific reasoning competencies. Limitations emerge from a rather high degree of panel mortality which were addressed with different scaling approaches.