Quiz

I have my students either email me the errors (using copy/paste) or by posting in my "Any questions about chapter xx" forum at the bottom of every topic.  If they are correct, I fix the problem and award them one bonus point.  Bonus points can up their final grade by one grade category (such as from B+ to .  This method encourages students to read carefully, think about every question, and then report errors.  I use this bonus technique for more than just quiz questions, I use it for any error in my course.  Could be even a spellling error.  Oh, only the first student reporting the errror gets the bonus point.