Navigating the Need for Rigor and Engagement: How to Make Fruitful Class Discussions Happen. Teaching by discussion can also seem forbidding because it makes instructors uncomfortably aware of their shortcomings. Lecturers can delude themselves that their courses are going well, but discussion leaders know when their teaching is failing to rouse the students’ interest by the indifferent quality of responses and the general torpor of the class. Why do we lecture so much? All teachers experience a tension between the need for engagement and the need for rigor. Without rigor, the students won’t learn what we want them to; without engagement, they won’t learn anything at all. Realizing that students need to discuss is helpful, but actually knowing how to make them discuss is another matter—it’s a skill that has to be learned. The challenge is not getting them to talk, but doing so without sacrificing too much rigor—how to ensure high-quality thinking and talking which engages the whole class. Here are some rules to consider.