In addition to Karen's insight, I would add this: support materials should add depth to the training experience.
Learners don't want to be talked at by video/DVD/ software. The media experience should capture and engage the learner while outlining the learning points. The support materials should expand on the learning points to connect with the learner and his/her environment. What is in it for them; why is the learning relevant to their work environment; and what are the benefits, i.e. why is the training worth their time.
If the training is trainer-led, then the support materials should include group activities and discussions that go beyond what was included in the video to provide learners the opportunity to connect the learning to their world through experiential activities, if possible, and discussion so everyone can learn from one another (for example, realistic customer problems and scenarios in customer service training).
If the support materials are self-study, the support materials should force the learner to think beyond what was presented in the video to again, connect the learning to his or her work environment.
If the support materials don't add value to the learning experience by broadening what the learner walks away with (in knowledge and/or ability), then they aren't "supporting" the training.
Writer and Training Advisor
Media Partners Corporationwww.media-partners.com