Brilliant. If i understand it correctly, the crucial insight is modeling a test taker's answer to a question as an adversarial game between the question and the test taker (eg, correct answer, the test taker wins). In the test-preparation business, the significance of this must be huge--a student doesn't have to sit down and take an
entire 'simulated' test to have a good sense of what their actual score would be; instead a relatively small number of carefully chosen questions will give an accurate prediction. Aside from score prediction, this methodology gives you immediate insight into which subjects a student should spend their prep time and at what level.
for those of with children not too far from college age, i hope this is reasonably priced.