I recently got to participate in a psychological experiment for programmers. A friend of mine, Mike Hansen, is doing research on how people comprehend programs. The goal is to figure out some way of measuring what features in programming systems help programmers understand wht they are doing, and how this can be used to make systems that lead to higher quality software. Mike is currently running an experiment where he shows people several short Python programs and asks them to tell the output of the program. The test subject is sitting in front of an eye tracker, so afterwards Mike can see where you were looking at various times during the experiment.