Intriguing study by SRI for the Dept. of Education that found that over a 12-year span, 99 studies of quantitative comparisons of online and classroom performance for the same courses. The analysis for the Department of Education found that, on average, students doing some or all of the course online would rank in the 59th percentile in tested performance, compared with the average classroom student scoring in the 50th percentile. That is a modest but statistically meaningful difference.
Study Finds That Online Education Beats the Classroom – NYTimes.com.