According to a recent article in the Chronicle of the Higher Education, it is found in a new study that many online instructors aren't taking advantage of interactive instructional tools like online video. Instead, the professors are relying on static (i.e., text based) course materials and assignments. These text-based course materials aren't likely to motivate students very much.
For instructors who are using or planning to use video in their courses, I would like to introduce the 'Video Ant (http://ant.umn.edu)', an easy video annotation tools created by U of M.
Using video ant, students can critique and annotate their idea about a video on Youtube or Media Mill.
You can find more information and video tutorials of Video Ant in Video Ant Blog.
As an example of utilizing the Video Ant, Tani Bialek, an instructor in OLPD let her online course students find a video on Youtube related to the course topic. And then, students are required to discuss, critique, and annotate it. The annotated videos are then posted on the Moodle site for all students in the course to view.
Read more about Bialek's story in another TEL blog entry.