Didactical design research of quadratic function based on learning obstacle and learning trajectory

Abstract

Students understanding on the topic of quadratic equation and quadratic function is separated each other, whereas both are interconnected. This research aimed to formulate a didactic design, which will help junior high students understand the linkage between both topics. By employing a didactical design research (DDR), this research involved the process of repersonalization and recontextualization of quadratic function to explore the learning trajectories and learning obstacles within such a process. This design aimed to represent the context of the assigned problem, and was analyzed through the following steps: 1) the explorative prediction of students' responses related to the assigned problem; 2) collaborative learning to lead the students in understanding the linkage of both concepts: Quadratic equation and quadratic function. Assigned by a contextual problem related to quadratic function, the students could widen their understanding about quadratic equation, but simultaneously encountered difficulties in relating the topic with quadratic function. In this case, collaborative learning helped them in doing so.