[curryst]

Long form answers (and college courses in general) are graded relative to your peers, whereas certificates aren't, which creates a huge difference. Even long form answers that aren't actually bell curved at the end, the person grading it has still read the best answers and the worst answers, and they're probably going to grade relative to that.

That precludes having studied "enough". "Enough" is measured relative to your peers, not to how hard the exam is. As long as someone else is studying, "enough" is a moving target. On a certification, I can check out how hard the exam is and study just enough to pass it. If I know for a fact that the exam isn't going to test comprehension, just recall, and that I'm not going to fail because someone else studied enough to comprehend, it makes sense to just memorize the recall portions.

Certifications would do better if they went the same way. For each group of people taking the test, curve the test so that some minimum, fixed percentage of them fail. Let's say it's 20%; so for every group of 100 people taking the test, at least 20 of them will fail (although it could be more if you set a floor on the lowest score you will allow to pass). Even if the exam doesn't test comprehension, I'm willing to bet that most people would pick it up just through studying.