AbstractA number of students who are educated to be primary and secondary school teachers still have problems in designing lesson plans. In this research, an instruction model for improving the ability of students in designing the lesson plans was developed. The instruction model was based on the theories of constructivism and metacognition. The research activities consist of 4 steps as follows. Firstly, a learning unit was created by using the backward design approach. Secondly, an instruction model was designed by employing the theories of constructivism and metacognition. Based on this instruction model, the lesson plans of the learning units were prepared for teaching the students. Thirdly, 18 students of Nakhon Pathom Rajabhat Universi...