This research investigated the impacts of active learning environments and instructional methods adapted to such environments on the academic performance of computer science students. Two consecutive studies involving a total of 267 novice students in the same course were conducted across two different semesters. The course was taught by the same instructor and set up with two different sections. One section was taught in a conventional lecture hall, while the other was taught in an active-learning classroom with adapted instructional methods. Active learning environments and the adapted instructional methods were found to have significantly positive effects on students' learning outcomes. Fine-grained results grouped by major were discussed. The findings of this study demonstrate positive effects of active learning environments in computer science education, thereby adding to the literature on both computer science education and learning environments.