A new analysis of existing online-learning research by the U.S. Department of Education (ED) reveals that students who took all or part of their class on line performed better, on average, than those taking the same course through traditional face-to-face instruction.

Most of the studies examined by researchers dealt with college-level courses, and ED officials cautioned against generalizing the report’s findings to the K-12 level. Still, the report could help educators as they seek to create effective learning environments for all students.

The detailed meta-analysis is part of a broader study of practices in online learning being conducted by SRI International for ED’s Policy and Program Studies Service. The goal of the study is to “provide policy makers, administrators, and educators with research-based guidance about how to implement online learning for K-12 education and teacher preparation,” says the report.

The study says online learning is deserving of analysis, because it is one of the “fastest growing trends in educational uses of technology.”

“Studies of earlier generations of distance and online learning courses have concluded that they are usually as effective as classroom-based instruction,” said Marshall “Mike” Smith, a senior counselor to Education Secretary Arne Duncan. “The studies of more recent online instruction included in this meta-analysis found that, on average, online learning, at the post-secondary level, is not just as good as but more effective than conventional face-to-face instruction.”

A systemic search of research literature from 1996 to 2008 identified more than a thousand empirical studies of online learning. Analysts screened these studies to find those that contrasted an online to a face-to-face condition, measured student learning outcomes, used a rigorous research design, and provided adequate information to calculate an effect size.

As a result of this screening, 51 independent effects from 46 different studies were identified that could be subjected to meta-analysis.

From these studies, researchers sought to address four specific questions: How does the effectiveness of online learning compare with that of face-to-face instruction? Does supplementing face-to-face instruction with online instruction enhance learning? What practices are associated with more effective online learning? And, what conditions influence the effectiveness of online learning?

While the project’s main goal was to research online learning for K-12, the report noted that only a few rigorous research studies have been published on the effectiveness of online learning for K-12 students. For this reason, the report states that “caution is required in generalizing the study’s findings to the K-12 population, because the results are for the most part on studies in other settings, such as in medical, career, military training, and higher education.”

The report also said its meta-analysis differed from recent meta-analysis of distance learning in that it limited the search to studies of web-based instruction (a limitation that eliminated studies of video and audio-based telecourses or stand-alone, computer-based instruction), included only studies with random-assignment or controlled quasi-experimental designs, and examined effects only for objective measures of student learning (discarding effects observed from student or teacher perceptions of learning or course quality).

Researchers also distinguished entirely online learning from blended, or hybrid, learning–online combined with face-to-face instruction–because while entirely online learning is “attractive” on the basis of cost savings and convenience, blended learning “needs to be more effective than conventional face-to-face instruction to justify the additional time and costs it entails,” according to the report.