Stephen,
I would start with a blend of both to get a "read" on the students. Deliver a mini-lecture of 15-20 minutes and then do an activity that has the students using the covered content, such as small group problem solving or a case study. You will quickly see how they respond. Most classes work well with this combination and you will be in good shape to continue this blending. In addition, with this blending approach you will be appealing to the different learning preferences of your students and this will help to keep them engaged as well.
Gary
Gary… >>>