Book excerpt: Essay from the year 2024 in the subject Didactics - Physics, , course: Philosophy of Science Education, language: English, abstract: This study investigates students' interest and achievement as well as how much teacher motivation and expertise predicts these things. It is thought that both student engagement and achievement are desirable results of classroom learning. Previous study has shown that teacher motivation is a key element impacting students' engagement, while teacher pedagogical content knowledge has been recognized as a strong predictor of student accomplishment. Until date, nevertheless, the majority of research has either examined knowledge or motivation (from both the teacher's and the students' perspective); it has seldom looked at both at the same time or examined the instructional mechanisms that are thought to enhance the alleged benefits of teacher motivation and knowledge. Using a multi-method approach to combine data from test instruments (teacher pedagogical content knowledge, student achievement), questionnaires (teacher motivation, student interest, student perceived enthusiastic teaching), and videotaped instruction (cognitive activation rated by observers), this study examines 48 physics teachers and their classes in Upper East and Upper West region of Ghana. The hypothesis that teacher pedagogical subject knowledge positively predicted students' achievement was supported by multi-level structural equation modeling; cognitive activation acted as a mediating factor in this relationship.