It seems to me that a fairer approach would be to set up a credit scheme. E.g. for each mistake that I spot in the lecturer's notes (or in the exam itself, for that matter), I should be given a "freebie", i.e. I don't lose marks for making one mistake in my exam. In the case of the book, these mistakes would typically be corrected in the next printing, so they could say that for each one I spot, I get a discount off the price of the next printing/edition, up to the point where I get a free copy of the new book. Bruce Schneier has done something similar with his book "Applied Cryptography", saying that he'll send a free copy of the source code to anyone who reports an error (which you would normally need to pay for). And as
It just gets frustrating - I think "If they're so smart, and I'm so stupid, then how come I can rip holes in what they've written? Or if they're not so much smarter than me, then how come they've all been given PhDs, when I get rejected?" I know that's unfair - if I wanted to do a PhD in algorithms then I'd probably be accepted. But it does annoy me. And as I find more mistakes, the tone of my email shifts. E.g. I started out by saying "In figure 3.27, the task decomposition seems a bit odd." That section now begins "Frankly, figure 3.27 is a complete mess." I may edit that again before I send it, but I've already exercised some restraint by not adding "I can only assume that whoever wrote that was drunk at the time."
Gah. Still, anger can be a positive force, if it's channelled correctly. I'm now getting into the mindset of "Hah, I'll show them who the expert is round here. I'll write the best damn exam paper they've ever seen!" And maybe I can get a job as a proof-reader in the future...