Mediation Effect of the Improvement in Teaching Assistant Quality in Students’ Evaluations of Their First-Year Experience

In Japanese higher education, a first-year experience program is required for new university students with diverse academic abilities and motivations. In order to ensure the quality of such higher education, it is necessary to properly train and utilize teaching assistants (TAs). The University of Tokyo, a national Japanese university, also provides a first-year experience program called the "First-Year Seminar." This program started in 2015, aiming to promote problem finding and solving skills through the utilization of TAs who are required to engage students in the program. However, the causal structure of how TAs effectively work in class has not been confirmed. The purpose of this study is to verify the causal model from the perspective of educational practice using data from student evaluations of teaching. The training of TAs underwent radical reform in 2017. The multi-group mediation analysis between pre- and post-TA training reform showed that the specific and appropriate support actions of the TA affect students and teachers, thereby affecting the students' overall lecture satisfaction. The author found that TAs who did not give enough specific learning support and knowledge can have a significantly negative effect on students, faculty, and lecture satisfaction. Furthermore, the author showed the educational effects of TA development not only in selfevaluation by TAs but in the supportive relationships among faculty, students, and TAs. The results of this study demonstrate the structure of how TAs work towards their goal of supporting classes.