Off to exams again...
In half an hour I'm off to the last day of exams in medical genome analysis, and my last day of exams in this period.
It is twenty minutes oral exams where each student presents a project she did during the class, after which we shoot some questions about the project. This is pretty typical for how we run exams here at AU.
I am having some problems with this particular class, though. I am only censoring, and the two teachers on the class are running the actual examination, so I am not the only one with the problem.
The problem is, it is very hard to grade the students. The distribution of grades right now, two thirds into the exams, is this:
I keep track of the grades, the time each student actually gets, the time of day, and lots of other info in a spreadsheet - plus of course have comments on the exam in text files - just because I'm a data junkie (and a little bit in case anyone complains about the exam later on).
The distribution looks a bit like a mixture, where you either get 12 - the top grade - or a normal distribution around seven. The latter is how it is supposed to look, really. Like this one, from string algorithms I taught last term:
UB means that the student didn't show up, and 0 that they failed, so those should not be normal distributed... the rest look okay.
I'm not sure that it is such a mixture, really, what is going on, though. I think it is more that the 10s end up in 7 or 12 - most likely the latter - and what we really have is a distribution with a mode at 12 and that then drops off as the grades gets lower.
Now, there is not an inherent problem in giving too many top grades. I don't think any of the grades are incorrect when comparing the exam performance against the learning goals of the class, and that is of course what we should grade against.
It just looks like the requirements for the exams are such that it is too hard to graduate the best of the class. There is essentially no differentiation between the good and the very best. We should be able to differentiate between them. We need that differentiation to pick the post grad students out of the pack. Here, we just cannot, 'cause as long as they meet all the course requirement they should get the top grade.
We've talked a lot about this the last two days. We cannot change the requirements now, of course, but something must be done before the next class.
It is just not obvious what. The learning goals really do match what we want them to learn. Maybe it is just the examination that must be changed, so we have a better way of testing how deep an understanding they actually have on the subject.
I have no idea how to do that, though. I find doing that a lot easier in mathematics or computer science classes, but this is really a class about the practical problems in medical genomics, and I do not have enough experience in examinations in something like that.
I guess we need to do some serious thinking about this...