Engagement has been viewed as an important construct to understand students' learning performances in classroom settings. Taking an interactive perspective, the study investigates ninth graders' cognitive, emotional, and behavioral engagement in teacher-centered (TC) and student-centered (SC) technology-enhanced classrooms. 54 students from two science classes in Taiwan participated in this study. Multiple sources of data were collected during a 3-week instructional unit. The statistical results showed that although students in the SC class reported having significantly higher emotional engagement, the emotional engagement level had no impact on students' learning achievement. Analyses of qualitative data showed that students in both classes spent a majority of class time on cognitive involvement in learning activities, but there were qualitative differences in cognitive and behavioral engagement between the two classes. One type of activities that did not occur in the TC class was making reflections in which students in the SC class self-assessed what they did. In addition, the SC class usually interacted through group discussions provoked by the simulations, whereas the TC class frequently interacted through initiation-response-evaluation sequences and engaged in student-initiated discussions. The findings suggest that both instructional approaches promoted students' conceptual understanding and provided students with different opportunities to engage in science learning. (Contains 5 figures and 4 tables.)