A new study examined more than a thousand empirical studies of online learning from 1996 through July 2008. The resulting report, Evidence-Based Practices in Online Learning: A Meta-Analysis and Review of Online Learning Studies (2009), found the following key finding:
• Students who took all or part of their class online performed better, on average, than those taking the same course through traditional face-to-face instruction.
• Instruction combining online and face-to-face elements had a larger advantage relative to purely face-to-face instruction than did purely online instruction.
• Few rigorous research studies of the effectiveness of online learning for K–12 students have been published. The systematic search of the research literature found just five experimental or controlled quasi-experimental studies comparing the learning effects of online versus face-to-face instruction for K-12 students. As such, caution is required in generalizing to the K-12 population because the results are for the most part based on studies in other settings (e.g., medical training, higher education).