If participants in a virtual session know exactly what’s going to be happening in the meeting or they know exactly when and how they will be called upon, then they can tune out until it gets to the part where they are required to participate. Therefore incorporating uncertainty as to when and how participants will need to participate will force those participants to keep attention on you, the speaker and or the topic at hand.
When you are designing your class outline or meeting agenda plan to have interaction every 30 seconds to a few minutes. Make sure that your participants do not know when that interaction will be. This makes it very hard to not pay attention because they will never know when they will be called upon. Use a phrase like this to communicate this: “In a moment I will choose a random person to…