I feel like I don’t have control of the discussion; we are getting off-topic. Because the substantive content of the discussion is generated by students (first on their own, then in groups), you may find that you have less opportunities to intervene and manage the focus of class discussion (both when students are discussing in small groups, and when they are sharing with the class).
Listen in to small-group discussions. When students break apart into small groups, work your way around the class and listen to their discussions. If these discussions get significantly confused or off-topic, gently intervene (ask a helpful question, clarify a relevant concept, etc.). If you can keep the small group discussions focused and productive, your reconvened full-class discussion will likely also be focused and productive.
Provide a framework. The questions you provide students with at the start of this format provide a framework for all the discussion to follow, so be thoughtful about the questions you ask students to answer and how you ask them to answer. Be explicit about what topics or material, if any, you want students to consider in answering the questions, and make clear what a strong, thoughtful answer involves (perhaps even give an example).
Let go. As noted, one of the strengths of this activity is that it puts students more in control of the discussion. By relinquishing some of this control, you invariably allow for a little more unpredictability and possibility of error. That’s OK. Students can learn a lot from their mistakes, and a discussion section can be a great, safe place to make such mistakes. Moreover, by giving students that control, you also allow for the possibility of viewpoints that you hadn’t considered (and that your students perhaps didn’t know counted as legitimate viewpoints), as well as the possibility of having discussions on relevant topics that students know better (fields outside of your own, personal values, etc.).
In the full-class discussion, students are just stating their answers and not discussing them. After reconvening from their small groups, students may proceed to only report their answers and the outcomes of their small groups’ discussions, rather than engaging in a new, full-class discussion.
Give and repeat clear instructions. In any multi-step activity, there is a chance students will fail to understand or lose track of the functions of the activity. As you reconvene for the full-class discussion, make clear that students need to continue to discuss the views on hand.
Model responding. When an individual student gives their answers, ask appropriate questions and make relevant suggestions (after giving time for students to jump in of their own accord). Encourage students to follow up. As the teacher, students implicitly look to you to model behavior.