Quick post with a reference to an article by Patricia Duebel I highly recommend for anyone who'd like to know more about Instructional Design (ID) for online-based learning environments.

An Investigation of Behaviorist and Cognitive Approaches to Instructional Multimedia Design
Journal of Educational Multimedia and Hypermedia v. 12 no. 1 (2003) p. 63 90

Thanks to Chris Teplovs for including this reading in this semester's section of CTL1922 at OISE/UT.

The paper FULL of great research and offers practical design and implementation "scaffolds" and examples.