Abstract
Previous research on providing feedback on public speaking has investigated the effectiveness of feedback sources, namely teacher feedback, peer feedback, and self-feedback, in enhancing public speaking competence, predominantly individually. However, how these sources of feedback can be collectively harnessed to optimize learner engagement and public speaking performance still warrants further investigation. Adopting a pre- and post-test quasi-experimental design, this study randomly assigned four classes to four feedback conditions: Group 1 received teacher feedback, Group 2 self-feedback and teacher feedback, Group 3 peer and teacher feedback, and Group 4 feedback from all three sources. Both student engagement, measured using the Public Speaking Feedback Engagement Scale (PSFES), and their public speaking performance ratings, assessed using the Public Speaking Competency Instrument (PSCI), were validated using Rasch analysis. The inferential statistics revealed that Group 3 showed significant improvements across nearly all three dimensions of engagement, whereas Group 2 experienced significant declines in all dimensions of engagement except behavioral engagement. Group 3 demonstrated significantly greater engagement gain compared to Groups 2 and 4, indicating the synergistic effect of peer and teacher feedback in contrast to the limited impact of self-feedback. Additionally, all groups demonstrated significant improvements except for Group 2, which showed significantly lower improvement compared to Group 4. The following correlation analysis identified a significant correlation between the gain of students' behavioral engagement and the gain of public speaking performance, whereas such association was absent between cognitive or emotional engagement and public speaking competence. This study suggests that peer feedback should be preceded by group discussion and supplemented with teacher feedback in classes for enhancing the teacher-student dialog, while self-feedback should be conducted after class to improve student engagement and public speaking performance.