Performing research and writing a thesis are two of the requirements for a masters degree from the Division of Science and Math education at Michigan State University.
For my research topic, I decided to write web pages for my senior physics class. Some students would receive the standard instruction I usually provide and some would only use the internet to view class materials and solve online problems in our school media center without any supervision at all. After the unit was completed, both groups were brought together and given the same test. The class size was 19, and about a third of these participated in the online sections.
This process was done two times, first for two weeks with a unit on vectors, and then for two weeks with a unit on momentum. The results of the unit tests showed an advantage for the in-class students in the verctor unit with 68% in class vs. 61% online and a difference of 76% in class vs. 75% online for the momentum unit. Other variables could have impacted these results, but the two groups performed similarly on the two tests. Students in the study for the most part enjoyed the experience and felt that they gained from it. As a result, I feel confident in stating that online courses can effectively teach high school students, and that the use of online materials at least as a supplement to regular coursework is a worthwhile endeavor.
The software has changed a lot since my thesis. You can learn about it at: http://loncapa.org/
Also visit the DSME at MSU, click this link: http://www.dsme.msu.edu/
Comparison of Online Coursework to Traditional Instruction