The purposes of this study were twofold. The first aim was to design and develop a clicker-based instructional model known as Clicker-Assisted Conceptual Change (CACC), based on the cognitive conflict approach for conceptual change, to help students to learn scientific concepts. The second aim was to determine the beneficial effects of CACC on students' scientific learning and to explore how CACC might achieve these benefits. Introductory physics was the learning subject, and a mixed-method embedded observation and interview methodology within a quasi-experimental design was used to address the second aim. The participants in this study were 275 first year undergraduates from 6 classes. One class was selected as the experimental group (50 first years) and the other 5 classes were selected as the comparison group (225 first years). The results show that the experimental group who used CACC performed significantly better in the comprehension test than did the comparison group, who used common instructional methods. However, the performance of the calculation test did not differ significantly between the two groups. Several benefits and challenges of CACC are used to explain these findings based on the observational and interview data. Finally, recommendations for future studies on the application of clickers are provided based on this work.