It is difficult to consistently apply the same criteria to all students for written assignments, especially when there are a large number of students. In this study, a report grading method that introduces mutual evaluation among students and grader evaluation was applied to a written assignment for an on-demand class with more than 1,000 students that the author oversees, which is scheduled to be submitted to this conference. The results showed that 1. The correlation between the results of the scoring by the method and the results of the teachers' scoring was very high and that it was effective as a scoring method, and 2. furthermore, by analyzing the results of the peer evaluation, it contributed to the improvement of teaching.