Modelling and analysis of prospective biology teachers' professional knowledge on handling of graphs

Diagrams play an important role for the sciences and their teaching. Based on the current literature on diagrammatic knowledge and teacher professionalism, components have been worked out which prospective biology teachers should be familiar with to be able to effectively teach the use of diagrams in their lessons. The aim of this article is to specify the components of the diagram-specific content knowledge and the pedagogical content knowledge as constituent parts of the teachers' professional knowledge and to identify their interrelationships. These components served as a basis for the theory-based development, validation and test of the test items. The questionnaire-based study included 442 teacher training students from 13 universities. It is with the help of the structural equation model that the interrelationships between the components were analysed. It shows that the integration of text and diagrams acts as mediator between the expert knowledge and the facets of the pedagogical content knowledge. The findings will fall within the framework of the didactic research of teachers' professional knowledge and its consequences for the teacher training in natural sciences will be discussed at the end of this work.