So, I just graded the last final essay exam from Spring 2012 NLM 160, Voluntary Action and Community Leadership. Over half the class got an A on the exam, and I am very happy with that. I know folks will say that's proof the exam was too easy, but I think it's proof that I coerced them both to read the material and to think.
As at least a modicum of proof that it's not because the exam is too easy: when I queried my students as to whether the midterm - on which they also did quite well - was too simple, the class emitted an immediate, long, low groan. My exams aren't that easy. But if you are good at following directions - all of them - it would be difficult to do poorly.
The key is in the directions.
Each question contains a reference to a very specific set of readings - usually a chapter from our text or one or two complimentary readings or audio visual presentations - containing the exact information they need to answer the question.
Then I ask a question - from real life - either their group work, their personal experience or from a case study. They must apply the information in the readings to the situation at hand to answer the question. And, they have to provide a citation to the exact page in the reading they leaned on to answer the question. This forces students to get into the book, figure out what's in there, and further more, figure out what those ideas can contribute to the situation in the question. This is what I call a "learning exam."
I can easily tell from the depth of their grasp, who's been keeping up with the readings all semester. Those who are with it display amazing, creative application. But for some of my students, this will be the first time all semester they crack the book. One of my students even admitted to me on the eve of the midterm that she didn't yet own the book!
One of my older students once lamented to me that a couple of the younger students in her group rarely did their reading. I pointed to my exams and asked if the way I structure my exams make more sense in light of that fact. She suddenly got it.
NLM 160 is a large class, and asking for essays is perhaps a stroke of stupidity on my part, since I have to grade somewhere between 60 and 80 exams, twice a semester, depending on class size. But I've discovered I'm not really happy unless my students learn, and the exam is the only way I can guarantee that students must crack those books at least once if they want to get out of my classroom.