[The Lone Ranger]

Grading exams can be a really depressing activity. These kids can memorize, but most of them can't think or analyze to save their lives. It seems like every season, they get less capable.

A colleague has a chart posted next to his office door, listing the average score on the Chemistry Placement Exam, which is given to all the incoming Freshmen. His records go back some 20 years now, and the trend line is very disturbingly negative.


They've been taught how to memorize, but not to analyze. The worst part of that is that it's painfully obvious that -- no matter how many times my colleagues and I insist that this is the worst possible study strategy (other than not studying at all, I suppose) -- most of them think that the way to "prepare" for an exam is to spend the night before memorizing the definitions of each term. This might earn them a passing score on the exam, but then they immediate perform what one of my colleagues calls the "hippocampal flush" and forget every bit of it.

The result, as I've seen time and time again is something like this: On Monday, I'll give an exam that covers, say, diffusion. Each student will dutifully circle the correct definition of "diffusion" on the exam sheet -- and then promptly forget it. The very next morning, we'll have a lab to explore how diffusion works -- and not even one of them will be able to correctly define the term, much less explain how it works.


So anyway, this exam covered photosynthesis. One of the essay questions asked them to explain the differences in how C3, C4, and CAM plants perform photosynthesis. This question could be answered in just 2 or 3 sentences (for which they would receive full credit) if only they could remember what rubisco is and what it does, what photorespiration is, and how CAM plants can avoid both photorespiration and water loss.

It was simply shocking how many of them instead wrote some variation of "CAM plants don't need light to perform photosynthesis".

I'm guessing that what happened is that the people in question were able to recall only two things about photosynthesis: 1.) that some [some, I stress] of the reactions that are part of photosynthesis don't require light to be present [which is why they're called the light-independent reactions] and 2.) CAM plants open their stomata only at night [this is an effective water-conservation mechanism]. From these half-remembered facts, they evidently concluded that CAM plants don't need light to perform photosynthesis.

Aside from the fact that -- having seen this response before -- I specifically and repeatedly stress in class that photosynthesis absolutely does require light, you'd think that the name alone would be a big ole clue that light is kind of necessary for photosynthesis. Yes, astonishingly enough, photosynthesis requires light.


Some of my colleagues have told me that they nowadays routinely add some 40 points to each exam score, in order to bring the average scores up to the point that at least half the students are actually "passing." There are times when I feel something approaching terror when I contemplate our future.