How does the effectiveness of online learning compare with that of face to-face instruction?

Looking only at the 27 Category 1 effects that compared a purely online condition with face-to-face instruction, analysts found a mean effect of +0.05, p =.46. This finding is similar to that of previous summaries of distance learning (generally from pre-Internet studies), in finding that instruction conducted entirely online is as effective as classroom instruction but no better.

Does supplementing face-to-face instruction with online instruction enhance learning?

For the 23 Category 2 contrasts that compared blended conditions of online plus face-to-face learning with face-to-face instruction alone, the mean effect size of +0.35 was significant (p < .0001). Blends of online and face-to-face instruction, on average, had stronger learning outcomes than did face-to-face instruction alone.

barbara means et. al

Means, B., Toyama, Y., Murphy, R., Bakia, M., & Jones, K. (2009). Evaluation of evidence-based practices in online learning: A meta-analysis and review of online learning studies. U.S. Department of of Education, 94.