According to a meta-analysis by the US Department of Education, face-to-face courses are less effective than online and blended learning. They caution against viewing this as simply a matter of the medium though. It's the changes in what online and blended learning allow (like opportunities for collaboration) that are likely making the difference.
Direct link to PDF: http://www2.ed.gov/rschstat/eval/tech/evidence-based-practices/finalreport.pdf
Literature review with guidelines for using multimedia effectively for learning. Quick summary of practical tips for educators.
(also found at http://portal.acm.org/citation.cfm?id=1027892)
Sloan-C report on online learning in US higher ed. Among the findings:
- 12% growth in the last year
- 20% of students took at least one online course in fall 2007
- Current economic problems (rising unemployment and fuel costs) are predicted to increase demand for online learning
Network analysis in online discussions in two classes shows, not surprisingly, that asking probing questions and challenging posts results in more learner engagement than simple "cheerleading" posts like "Great job!"
New link: http://www.eschoolnews.com/2008/05/08/online-insight-challenges-beat-cheerleading/