Traditional lecture-based instruction is increasingly being replaced by student-centered models that emphasize active learning and collaboration. The flipped classroom is one such approach, and when combined with collaborative learning, it has the potential to enhance student engagement and academic performance in higher education. Although research on flipped classrooms has expanded internationally, few studies have examined their application in open university contexts, particularly in Thailand. This study investigates the impact of a collaborative flipped classroom model on third- and fourth-year students at an open university. A mixed-methods design is employed: surveys measure student engagement, academic performance, and satisfaction, while focus group interviews provide qualitative insights into learner perceptions. Quantitative data will be analyzed using SPSS to identify trends and correlations, and thematic analysis will be applied to qualitative findings. It is hypothesized that the collaborative flipped classroom will improve academic outcomes and foster greater satisfaction by promoting both peer interaction and independent learning. The results are expected to provide evidence on the suitability of this model for open universities, where learner autonomy and flexibility are crucial. Findings will contribute to the broader body of knowledge on student-centered pedagogy and inform future curriculum innovation in higher education. 

Keywords: Collaborative learning, flipped classroom, mixed-methods study, open university, higher education, student engagement, academic performance, Thailand, educational innovation.