High quality science and mathematics education is central to economic prosperity. This study will achieve two outcomes. Firstly it explores the importance of subject matter knowledge in teaching. Much has been studied about the knowledge of teachers but limited research has been conducted with teachers who have substantial subject-matter knowledge. These findings will inform the current debate about the appropriate models of teacher education and the balance of emphasis on content knowledge and pedagogical knowledge. Secondly, given a number of attempts to attract mid career professionals with high qualifications to teaching, the study will provide evidence on how these people transition to their new careers and what support is needed.**Grantor:Australian Research Council (ARC)**External Ref:DP0984349