eLN members may be interested in research by Dr Traci Sitzmann of the ADL Co-Laboratory and Dr Robert Wisher of the US Department of Defense which consisted of a meta-analysis of 96 different studies. The study seems to conclude that it's the instructional method, not the delivery medium, that makes the difference. When web-based instruction and classroom instruction that have similar methods (feedback, practice, etc.) are compared, there's little or no difference in outcomes.

http://adlcommunity.net/mod/resource/view.php?id=202