An open-book exam is pretty self-explanatory: you’re allowed to write the exam with all of your books open. That usually means you can bring in your notebook, textbooks, calculator—you name it. So when your professor announces that your exam will be open book, you think that you hit the jackpot, right? Maybe, but it’s more likely that your professor is testing your research skills. Law students, for instance, are very familiar with the open-book exam, but no one ever said that law school is easy. They can’t possibly memorize every relevant legal case, so their exams are open book. But unless they’ve studied ahead of time, they won’t know how to find the answers, even if the answers are right in front of them.