The Impact Of Teachers' Pedagogical Content Knowledge On The Teaching Task Design

To a large extent, teacher knowledge has an impact on teacher's decision-making and behavior in the classroom, and teacher's pedagogical content knowledge reflects the professional characteristics of teaching. Researching on the relationship between pedagogical content knowledge and teaching task designing can provide us with a way to understand what kind of knowledge teachers need in their teaching.Through hackling the existing research literature, it is found that studies on teacher's knowledge have different perspectives and orientations, and different researchers' understanding on the teacher knowledge has something in common. Many researchers believe that the pedagogical content knowledge has highlighted the professionalism of teachers, which contains the knowledge relevant to teaching. Teacher's pedagogical content knowledge has a direct impact on the design of teaching tasks.Taking two primary mathematics teachers as cases, this study examines the difference between expert teachers and non-expert teachers in pedagogical content knowledge and teaching tasks design, and tries to find how the pedagogical content knowledge affects their teaching tasks design. The study chooses an expert teacher and a novice teacher with the same teaching contents, using different research methods to collect data, such as participatory classroom observation, teaching video analysis, interviews, and collection of documents (mainly teaching plans). The study analyzes these data from the aspects of pedagogical content knowledge and the design of teaching tasks.The study found that the expert teacher has clearer and more accurate expectations for students' difficulties that they may encounter during the process of learning. He can express the framework of teaching objectives more clearly, while the non-expert teacher becomes unaware of his teaching objectives in the process of teaching. The expert teacher knows more comprehensively about the students' cognitive difficulties; while the non-expert teacher takes no notice of students' cognitive difficulties, merely following the contents of textbook. In the design of teaching tasks, the expert teacher is inclined to design the teaching tasks with emphasis on the links between concepts, guiding students to experience the problem situations, giving students the exploring space and maintaining the cognitive level of tasks. The non-expert teacher tends to use a series of hints to make students enter the established ways of thinking, reducing the cognitive level of tasks from a higher level to a lower level.The study found that teachers' pedagogical content knowledge has a direct impact on the design of teaching tasks. Firstly, in the design of teaching tasks, the expert teacher's understanding of the difficulties that students may encounter can help them integrate the specific subject content with the students' characteristics of thinking, providing the challenging space for students' thought. Then the expert teacher's understanding of the teaching objectives has a direct impact on the cognitive level of teaching tasks. Lastly, the understanding of the teaching difficulties also affects the clarity and effectiveness of teachers' teaching task design. Based on the findings, the paper puts forward some suggestions about the practice of teacher professional development and its further research.