Math teachers! I know this is a science and technology blog, but you MUST MUST MUST check this resource out! It is a site called ASSISTment, which has been developed at Worcester Polytech using grants from the US Dept of Education and the National Science Foundation. Which both mean that it is
The ASSISTment system provides students with two types of tutoring assistance--scaffolds and hints--when they answer a math question incorrectly.
This screenshot gives you a little bit of an idea of how it looks (I intentionally answered the question wrong, so that I would get a scaffold question):
You can log on to assistment.org to create your free account. There is an ASSISTment teacher wiki that has instructions on how it works, but before I found that I clicked around awhile and I figured some of it out that way.
If you are a teacher, you can even apply for FUNDING to create content for your classroom through a WPI program that is funded by the National Science Foundation. So, get some money for the time that you spend putting content on your ASSISTment account and share your data with them to improve the program. For that info, see the homepage.
Okay, so if you want to look at the data from the research, follow this link:
A Comparison of Traditional Homework to Computer-Supported Homework