This practice doesn't seem to be used at all in science, but occurs all the time in psychology, where they want there to be a set average for all classes. I'm pretty vehemently opposed to scaling people down on exams, and I think most students agree. However, it's still used, and I wanted to really look into the reasons both for and against it.
It seems that the main purpose of the practice is to prevent mark inflation. If you let students do well, that just means that every year the marks will just go up further, and soon enough, everyone will be getting 100% on exams (or at least an 85), and standards across Canadian schools will be shattered as everyone scrambles to give students higher marks to guarantee their entry into graduate programs. Chaos will ensue as schools try to identify which students are actually good at the subject, undeserving students will get in at the cost of the capable ones, the genius will be lost among the mass of mediocrity. Or will that actually happen?
Well, first of all, under what circumstances do professors scale marks down?
1.) The exam was too easy, and too many people did well.
-I would argue that this is the fault of the professor. If you design any sentient being that can read and understand English and can apply basic principles of logic to deduce correct answers, it's a problem with the exam. Ok, I know this is an exaggeration, but still- why are we punishing students for the mistake of a professor?
2.) The exam was hard, but students studied hard and did well.
-There are classes where students know the material is going to be hard. There are also classes where there there just happen to be lots of good students (honours classes, for instance), who might study hard and do well. It does happen- and when it does, I don't think those students should be scaled down, as they could just legitimately know and understand the material better.
I would argue that the doomsday scenario profs envision won't actually materialize.
First of all, there's nothing to say that a high average one year, or even on one exam, will create this upward spiral of grading. Just because one year's class happens to do well doesn't meant that this is going to be an on-going trend. Setting the class average to be 65% every year is simply not accounting for natural variation among the student population. You might get a brilliant group of students one year, and a terrible group of students the next year. If the aim is to compare students from year to year, then setting a set average doesn't do much in terms of establishing a scale of comparison, as the average is so sensitive to individual marks.
I also don't see anything wrong with people doing well on an exam that's designed to test their knowledge of the material (i.e. a fair exam). Theoretically, in a good class, students will study hard for an exam, and do well as a result. Sure, not everyone will study- and those people who don't will do worse, and score below average- and also probably do significantly (p<0.05) worse. Even if the instructor did compose an exam that could have been written by a student who never attended class or did any of the readings and just wrote the exam based on previous knowledge- scaling down only penalizes the people who did do well and who studied hard. Sure, it might be unfair to the person who studied lots and did as well as the person who studied little- but that happens even on difficult exams- and it's still unfair to scale the hardworking person down. Plus, if you are scaled down because the exam wasn't hard enough, there's nothing to say that you would have done just as well on a harder exam. There's also always the opportunity to make the next exam slightly more difficult so that you actually test students' learning and understanding of the material rather than things like previous knowledge, if this was the initial problem. In the case that the average is 'too high' on the harder exam, I would argue that students who perform well on a it still deserve good mark, regardless of what the average was 'supposed' to be. Considering the fact that most exams are quite similar from year to year, it makes no sense to scale a class down on an exam that achieved the targeted average in previous years- all the high mark indicates is that students learned the material well. Scaling down then simply makes the marking unjust, and removes motivation to study, because at that point your mark and your effort in the course are no longer correlated, as the mark you get for the course is not actually indicative of the effort or knowledge you attained over the term, but rather is indicative of the average your professor wanted the class to attain.
Then there's the second issue- not being able to separate the genius from the simply smart from the average if everyone ends up doing well on an exam. My first qualm with this belief is that I just don't think there are all that many geniuses floating around, and those who are indeed of superior intelligence will be able to prove themselves in some other way (show their brilliance through other projects, or during their grad school interviews, or through reference letters, etc.). But more importantly, if you're scaling everyone down, you're supposedly scaling the geniuses down as well, no? Or if you're not using a uniform scale, and giving the person who got a 98 a 92, but letting the person who got 100 keep that mark- you're essentially saying that the person who got 100 is smarter than the person who got a 98. In this case, though, the initial difference could have been a matter of one student getting one more question correct, and that could be the result of a random guess and simple luck rather than knowledge of the subject matter. So really, if we're trying to separate geniuses from a group, we should devise a matter of doing so that doesn't involve punishing everyone else in the group, and that relies less on things like chance and luck. I'd also argue that tests shouldn't be targeted at the 0.00001% of us who are brilliant, but that's a bit of a tangent to be written about some other day.
So why do profs scale down? Why have a target grade? Presumably to ensure that the average is consistent across all schools, or to prevent high marks from becoming meaningless- to which I have several responses. First of all, unless there's some sort of pact between schools or departments to set an average, there is nothing to prevent one school from deciding to give all their students marks of 80% and up for any given course. A good application review system will notice this, and probably judge applications based on either other factors, or else by looking at how the student did compared to the class average. Secondly, this notion of marks becoming meaningless when they're too high- and I'd argue that no, this isn't the case. I find that on the whole, it's not all that difficult to do well in a psychology class, if you actually a.) come to class b.) listen in class (This seems to be a problem for some, which is why b.) is its own category. There are some people who like to learn through osmosis and come to class and sleep.) c.) do the reading and d.) do some studying (i.e. memorize some material and understand it). This normally, provided that the person understands and knows the material, is guaranteed to get the student at least a 80 (I think. I haven't done the stats or anything, so this bit is more of a conjecture. But I think that in psych, at the very least, it must be somewhat true, although I don't know error margins). In this case, I don't think the mark is meaningless- I think it's just something the student is proud of. Also, this doesn't apply to the GPA booster courses, where you're asked things that seem to be common knowledge (Believe it or not, things like "does the Sun revolve around the Earth?". Answer at the bottom of the page, if you are unsure). But even in those courses, people somehow manage to fail the exam, even without the prof scaling down... It is not unfathomable, however, that everyone engages in these 4 sequences. It shouldn't be a surprise, then, when students do well. Low averages are based on the preconceived notion that students will slack off, not study, or be generally unintelligent- all of which I would dispute. So why base expectations on preconceived notions that are bound to fail every once in a while?
I think my argument is pretty clear- maybe not as clear as it would be had I written this at any decent hour, but clear enough nonetheless. Don't scale down. I'd further propose that marks in general aren't always indicative of either learning or achievement in the class. I'd also argue and that marks on transcripts should be given in relation to the average class mark- this allows application reviewers to really judge how well the student is doing in a class. If the transcript indicates that the student scored an 85 on an exam where the average was 80, that something different about the student than if he/she scored an 85 where the class average was 60. I'd be interested in seeing some of these ideas argued, at the very least. They might certainly reduce the problems people have with mark inflation, and might serve as better indicators of students' performance- and that, unless I'm hugely mistaken, is what the marking system is trying to ensure in the first place.
Oh, and the answer is no. The Earth revolves around the sun. For the physicists out there, I know this is probably a simplification, and if you look at the world in 16 dimensions, you can arguably say that there's some sort of complex pattern of movement where the two bodies, based on Someone's Law, revolve around one another, or something along those lines. But for our purposes, "no" is the answer.
Sunday, November 9, 2008
Scaling Down
Posted by Maria J. at 11:37 PM