Effects of an Interdisciplinary Science Professional Development Program on Teacher Pedagogical Content Knowledge, Science Inquiry Instruction, and Student Understanding of Science Crosscutting Concepts in Twelve Public Schools: A Multi-level Modeling St

Systematic studies on effectiveness of in-service teacher professional development (PD) are important for science education research and practice. Previous studies mostly focus on one certain aspect of the entire program, for example, effectiveness of PD on improvement of teachers' knowledge or students' learning outcomes. This study, however, explores a complete model of effectiveness of PD from the intervention of a PD program to teachers' improvement in knowledge and practice, to how teacher change influences students' beliefs, and finally to student understanding of interdisciplinary science concepts according to NGSS. The sample includes 5527 students in 200 classrooms within 12 schools. The results of multi-level analysis show that teacher attendance in professional learning communities (PLC) positively relates to their scores in pedagogical content knowledge (PCK) test and teachers' implementation of inquiry teaching benefits from adequate engagement in authentic science and engineering research. Furthermore, students whose teachers engage in longer periods of research perform significantly higher on the interdisciplinary science test. The mediation effects between PD intervention and student outcomes are explored. PD intervention helps teacher implement inquiry teaching in classroom, which directly influences student understanding of interdisciplinary science, self-efficacy in learning science, and understanding of Nature of Science (NOS). The later two factors also have positive impact on student understanding of interdisciplinary science.