This meta-analysis research estimated and compared the differences between the academic performance of students enrolled in distance education courses relative to those enrolled in traditional settings, as demonstrated by their final course grades/scores within the 1990-2002 period. Eighty-six experimental and quasi-experimental studies met the established inclusion criteria for the meta-analysis (including data from over 15,000 participating students), and provided effect sizes, clearly demonstrating that: (1) in two thirds of the cases, students taking courses by distance education outperformed their student counterparts enrolled in traditionally instructed courses; (2) the overall effect size d+ was calculated as 0.37 standard deviation units (0.33 < 95% confidence interval < 0.40); and (3) this effect size of 0.37 indicates the mean percentile standing of the DE group is at the 65th percentile of the traditional group (mean defined as the 50th percentile).
Shachar, M., & Neumann, Y. (2003, October). Differences between traditional and distance education academic performances: A meta-analytic approach. International Review of Research in Open and Distance Learning. https://doi.org/10.19173/irrodl.v4i2.153