A study released in May, 2009 by the US Department of Education shows that students in online learning environments outperformed those receiving face-to-face instruction.
The report was based on a systematic search of the research literature from 1996 through July 2008, and identified more than a thousand empirical studies of online learning. Analysts screened these studies to find those that (a) contrasted an online to a face-to-face condition, (b) measured student learning outcomes, (c) used a rigorous research design, and (d) provided adequate information to calculate an effect size. As a result of this screening, 51 independent effects were identified that could be subjected to meta-analysis. The meta-analysis found that, on average, students in online learning conditions performed better than those receiving face-to-face instruction.
A copy of the complete report titled “Evaluation of Evidence-Based Practices in Online Learning: A Meta-Analysis and Review of Online Learning Studies” is available from the US Department of Education at http://www.ed.gov/rschstat/eval/tech/evidence-based-practices/finalreport.pdf