As anyone who has taught for more than a week will tell you, the most clever and carefully planned classroom strategy can fall flat if your students balk. Active-learning strategies necessarily depend on student participation and, thus, are particularly vulnerable to student resistance.
Most of what we mean by "participation" involves students being willing to contribute constructively to class discussions. And we've all had classes in which, for whatever reason, students just don't want to talk. So how do you minimize that occurrence and lay the groundwork for active learning?
The first step is to prioritize discussion. It's important that you let students know that discussion is integral to the course, to their learning, and to their grades. Be explicit, early on in the term, about why it's important for everyone to take part in discussions. Devote a section of your syllabus to laying out that reasoning as well. Make participation at least 10 percent of students' final grades, and hand out interim participation grades regularly to remind students of their responsibility.
You can also enshrine discussion in the regular rhythm of a class period. Begin each class with a discussion question. Do that every time—perhaps allowing a few minutes for students to write down their thoughts first—and they will get in the habit of coming to class ready to talk.