What are we testing?

Day 3 of my four day vacation, called Fall Break. Mid-terms were as I predicted embarrassing. As part of my "relaxed fit semester" I gave my ethics students the following.

24 Questions in advance over the course of the semester.
I would write these on the board the week we studied their subjects, and I also included them on the class website. They had a review day to go over their answers with me in class. And, here is the kicker. They were allowed to bring any notes that they made (including a question by question set of pre-written answers if they constructed that). The mit-term exam consisted of 6 of those 24 questions, of which they had to answer Four.
Average grades for my two sections were 69% and 74% (the latter was for a 120 minute class rather than a 50 minutes).
Now, it is possible that the questions were so perplexing that even with the weeks of advanced notice the typical student could not grasp the answer. While they weren't the easiest questions, nearly everyone was simply a chapter sub-title reworked as a question (so studying should not have been too difficult).

This leads me to a hypothesis. I think my tests test something other than knowledge or intelligence. I think they test commitment. How much work is a student willing to do for a grade? Clearly, any student had the chance to get 100% percent by following these simple procedures (a) copy down the questions, (b) look up the answers (c) confirm the answers with me in class, or in my office hours (d) copy said answers on the test. Yet very few students seemed to do that, or do that properly. I suspect the reason was, my test was no high on their list of priorities. And that is fine, if a bit insulting.

So here is my question. Is commitment of this nature something worthy of testing and grading? In the long run, it won't really matter all that much if my students can remember the difference between Act and Rule Utilitarianism. So that was never something I was really interested in judging anyway. If grades are supposed to be evaluations of people's ability to learn (in some general way), then I am not sure my test provides a good gauge, since one could simply copy the answers from one document to another (though finding that information will likely result in some learning, I hope). My main concern is that commitment may not be something that I can teach. In other words, I am merely evaluating an independent feature of the students that my teaching has little bearing on. Granted, some of them may be inspired to levels of commitment by my stirring oratory, but I am dubious about that.
I've often thought that many tests end up testing something like the independent features: cleverness, memory, of people rather than the subject matter or what have you anyway, so I am not sure this is a particularly bad thing.
It may be of more value to say future employers to know just how committed a student can be to something not necessarily fascinating to them. Of course, at the same time, this may just be judging how interesting the subject matter (as taught by me) is to the students. In which case, poor average grades might be an indictment of either Philosophy or my teaching, or both.
Any hoo. Random thoughts.

Other lesson this term.
Just because they are Honor Students, does not mean they can operate independently.