Hi Elizabeth, One of the keys for successful teaching is pacing. Have your class laid out into 10-15 segments of lecture and then activity. This change of pace lets the students refocus their brains on different paths. They are using semantic learning for the lecture and then working memory with the activities with reinforces the semantic or content part of the course. After several of these 10-15 lecture/activity efforts stop and then do a group case study or problem solving project. This will serve to keep the students engaged throughout the four hour class. Let me know how you make out. Gary