Turning lectures into interactive, student-led question and answer sessions is known to increase learning, but enabling interaction in a large class seems an insurmountable task. This can discourage adoption of this new approach -- who has time to individualize responses, address questions from over 200 students and encourage active participation in class? An approach adopted by a teaching team in large first-year classes at a research-intensive university appears to provide a means to do so. We describe the implementation of active learning strategies in a large first-year undergraduate physics unit of study, replacing traditional, content-heavy lectures with an integrated approach to question-driven learning. A key feature of our approach is that it facilitates intensive in-class discussions by requiring students to engage in preparatory reading and answer short written quizzes before every class. The lecturer uses software to rapidly analyze the student responses and identify the main issues faced by the students before the start of each class. We report the success of the integration of student preparation with this analysis and feedback framework, and the impact on the in-class discussions. We also address some of the difficulties commonly experienced by staff preparing for active learning classes.