Research on improving free educational materials

Hi all. I'm a PhD student in computer science at CMU, working on how to provide technology that allows teachers to create, share and collaboratively improve upon a commons of educational materials.

In a previous study, participants made worked example problems to help teach the Pythagorean Theorem. Some teachers participated but most of the contributions came from non-teachers. This time I'm hoping to get more input from teachers!

If you're interested in this idea, please try out this web-based experiment. For your time you'll be entered into a lottery for Amazon gift certificates. The more you contribute, the more chances you get in the lottery. And high quality contributions get triple the odds, which should be easy for skilled educators.

Here's a link to the study,
http://education.hciresearch.org/pythagorean/improvement/

Friend me if you want to be updated on future such studies.

Thanks!

-Turadg