RESUMEN
BACKGROUND: Teaching assistants (TAs) play a crucial role in pedagogical practices, and the TA training has emerged as a vital strategy for enhancing teaching quality and fostering effective interactions. The self-efficacy of TAs can substantially impact their performance. Nevertheless, little research has focused on the change in TAs' self-efficacy following their training. METHODS: A self-control quasi-experiment was conducted to examine shifts in the self-efficacy of Tas at Peking University before and after their TA training. A questionnaire was used to assess the change, and the reliability and validity of the questionnaire was also calculated. A paired data rank sum test was used to analysis the changes in TA self-efficacy before and after training. RESULTS: A total of 372 TAs from School of Basic Medicine (N = 173), School of Pharmacy (N = 112), School of Public Health (N = 69), and other schools (N = 18) submitted complete questionnaires. The questionnaire showed a good performance in internal reliability and validity test (Cronbach's alpha index = 0.906, and KMO value was 0.903). Participants had a median total self-efficacy score of 88 and 85 before and after the TA training, respectively, which shows a lack in the total TA self-efficacy score following the TA training (P < 0.001). TAs who have no desire to becoming a college instructor have a higher self-efficacy when compared to TAs who have expressed neutral attitudes in becoming college instructors. CONCLUSION: The participated TAs display a lack of self-efficacy after attending the TA training at Peking University. Therefore, it is necessary to establish and strengthen TA's self-efficacy beyond academic skills when designing and delivering TA training programs at Peking University.