After MIT started providing access to a wide range of course materials on its OpenCourseWare website a few years ago, a number of other universities and colleges began to follow suit. As a result, users around the world now have access to a generous supply of such educational tools. One similar venture is the Open Learning Initiative website at Carnegie Mellon University, which provides access to a collection of "cognitively informed" online courses and course materials. Courses currently available online on the site include biology, calculus, chemistry, economics, and causal reasoning, along with a handful of others. For each course, visitors should read the background essay provided, as it will give an overview of what each course will cover, and how students can proceed. Of course, students are encouraged to give feedback as well.