Enhancing English Public Speaking Self-Efficacy and Performance Through a CDIO-Based English Course

This study investigates the impact of integrating the Conceive–Design–Implement–Operate (CDIO) framework into English public speaking (EPS) instruction for English as a foreign language (EFL) university students in Taiwan. EPS has been widely recognized as a critical competence in academic and professional contexts, yet EFL learners often struggle with anxiety, limited practice opportunities and low self-efficacy. To address these challenges, the study implemented a quasi-experimental design with two Freshman English classes: a control group receiving traditional presentation training; and an experimental group engaged in a CDIO-based presentation training. Over an 18-week semester, students’ self-efficacy was measured using a validated EPS self-efficacy scale, while performance was evaluated with a rubric assessing language use, content, organization and delivery. Pre-test results showed no significant differences between groups, ensuring baseline equivalence. Post-test findings revealed that the experimental group demonstrated significantly higher self-efficacy, as well as superior performance in content development, organizational structure and delivery techniques. However, no significant improvements were found in language accuracy and fluency. These results suggest that CDIO-based instruction enhances students’ confidence and competence in public speaking through authentic, project-driven tasks. The findings yield three key pedagogical implications: (a) integrating authentic, product-based tasks such as sustainable innovation pitches can foster mastery experiences and boost learner motivation and self-efficacy; (b) using CDIO's four-phase structure enables instructors to scaffold content and organizational development through guided brainstorming, outlining and rehearsed delivery; and (c) to address limitations in grammar and vocabulary acquisition, supplementary language-focused interventions such as vocabulary mini-tasks and grammar workshops should be embedded within the CDIO cycle to balance fluency with accuracy. These strategies can optimize the effectiveness of CDIO-based EPS instruction in EFL contexts.