Monday, December 01, 2008
Graduate Record Exams: Biochemistry, Cell and Molecular Biology
This is the time of year when some undergraduates are getting the results of the GREs (Graduate Record Exams) that they wrote in preparation for graduate school applications. I thought I'd take a look at the practice test for Biochemistry, Cell and Molecular Biology.
This isn't pretty. Many of the questions ask for specific details like what is the initial product of CO2 fixation in C3 plants? I know lots of departments that don't teach photosynthesis and CO2 fixation so students in those departments are screwed.
More importantly, I teach this in my introductory biology class but I tell the students that they don't have to memorize the details. They are allowed to bring their notes to the exam. I try to concentrate on basic principles and concepts and not on the names of enzymes and their specific reactants and products. In the case of CO2 fixation, the important concepts have to do with the way rubisco works, the usable product of the reaction (not the initial product), and a general understanding of how the original reactant is regenerated. They have to understand the overall stoichiometry of the pathway and how the pathway is related to the pentose phosphate pathway.
Here's the problem. Are teachers like me hurting our students' chances of doing well on the GRE by discouraging rote memorization and regurgitation?
Even worse, I teach that concepts like exergonic and endegonic reactions are almost useless in most cases because most of the reactions in a pathway operate at near-equilibrium conditions where ΔG = 0. Several of the GRE questions ask about exergonic and endergonic reactions. My students will not do well on those questions.
How common is this? Do any other biochemistry teachers find that there's a conflict between what they teach and what is taught at most other schools?
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16 comments :
Surely the better question to ask has to be "what does a practicing biochemist think of the GRE questions to the extent that the GREs purport to measure aptitude for biochemistry grad school?"
@AcidFlask - no, I think Larry's question is better, because he's thinking about things which are certainly within his power. He wants to teach his students well, and is concerned whether as an unintended side-effect of that he is somehow hampering their ability to score well in the GRE. One could of course also think of sending feedback to the people responsible for setting the questions on GRE.
@Larry - I guess the more motivated students should be able to look at sample tests and figure out how to prepare best, and I'm sure they only need to make some extra effort to supplement the sound grounding in Biochemistry that you undoubtedly provide them with.
GRE is basically a grad school entrance exam, right? What a moronic exercise!
I only had patience to go through first 20 questions. Turns out I answered only 13 questions correctly.
I am sure all of the grad students I trained scored much better than that.
My experience with the psychology GRE was that it fairly reflected psychology knowledge at approximately a second-year undergraduate level.
Students shouldn't be relying on their memories of old lectures -- they should be using them as a basis for restudying and relearning those kinds of specific details. For a good score, lots of studying is required using old textbooks and study guides.
The subject GRE is a decent predictor of first-year graduate study grades, with a correlation of between .30 and .35. This is just as predictive as undergraduate GPA.
Apparently it's not obvious to everyone, but science isn't about tests and memorization, it's about research and publications.
Science is not only boring but it's completely useless when taught as a series of unrelated facts to remember. I always like to quote Henri Poincaré on this;
"Science is built up of facts, as a house is with stones. But a collection of facts is no more a science than a heap of stones is a house."
Should details be taught (or overly emphasized) to undergraduates? Maybe not. An undergraduate degree is a prerequisite for acceptance to a graduate program. But it also stands on its own, and has other principles to consider.
People who go on to graduate school may understand that what they've learned in class to get their degree is not the only preparation they need in order to continue. They're probably self motivated enough to crack several biochemistry textbooks to try to understand the material from perspectives other than their profs'.
Hi Larry,
I would have loved to have teachers stress on us getting the concepts right, rather than the details. Here in India, it's very much rote learning (even at Master's levels) - and I hated almost every minute of it. The saving graces were a couple of profs who focussed more on getting the concepts, and on thinking of how they can be applied.
You can 'warn' your students - specify at the outset that if they want to do well in the GRE, they better rote learn, but you would rather have them understand concepts.
Scrap GREs. What an idiotic exercise - one would have hoped we'd be away from exams when dealing with Grad School. It's research, not high school.
I like to think that once you understand something thoroughly, the details should be easier to memorize, should you need to. Top-down, from big picture to specific details, rather than memorizing details for an overall process you don't understand.
All the same it seems like the GRE, MCAT and similar tests really miss the point, and we should be able to find a method of evaluation that actually involves assessing one's ability and understanding, not their likeness to a trained monkey. Of course this will come at the cost of decreased efficiency.
Same reason why organic chemistry, calculus and physics are taught in premed schools...to "weed out" the weak students, justifiably or unjustifiably.
I agree that a degree shouldn't be rote learning and graduate studies are predominately research oriented.
However, in psychology if one scored poorly on the subject GRE (maybe < 70th percentile?) it means they (1) didn't absorb a lot during their undergrad and (2) didn't care enough to study. These are not good signs.
How is one supposed to conduct research without a firm grounding in what's been doing previously? I see the basic facts are a prerequisite for doing more advanced work.
As has been stated above, the GRE tests the general knowledge students should have gained from the first half of their degree, not specific knowledge from upper level classes.
All this talk about 'just learn the concepts' sounds like a cop-out to me; you need to understand the concepts in addition to knowing scientific facts.
Having recently taken the biology GRE myself, I can confirm that there were plenty of conceptual questions on there, especially in the experimental section at the end (where you are given the details of an experiment and have to show that you have a good conceptual understanding of the experiment in order to be able to answer the questions correctly).
If students can't remember the basics, how do they expect to be decent researchers? How will they be able to assimilate much more complex and specialized knowledge that builds up on top of what they should already know? How will they know what questions to ask as researchers?
To be a good scientist, you need a good level of background knowledge. Of course this doesn't mean research skills aren't important as well - that's why grad schools also ask applicants about their prior research experience. They also get you to write a personal statement and have referees talk about you, etc. The GRE tests are just one part of the application process.
Larry is right, GRE, and unfortunately many biochemists all over the world, are all wrong about the testing and what is important. It's SO stupid to make biochemistry into a dead-boring exercize of memorization, yet many do just that. Those guys are KILLING biochemistry.
I have to disagree with Gibson here. The emphasis on concepts is not a cop-out, it's the opposite. Even idiots can memorize tons of facts, it's much harder to understand the concepts.
It's really unfortunate that you can get away with rote memorization in life sciences, it's much harder (if not completely impossible) to do so in mathematics/physics. Not that mathematics and physics are harder per se...
Hi
Science teaching is a apparently an old and worldwide problem.
The great R. Feynman wrote a wonderful piece in his "Surely you're joking Mr. Feynman" about science teaching in Brazil. If you don't know it, take a look at http://www.feep.org/articles/feynman.html. It was exactly about the memorization of scientific facts instead of real understanding of concepts.
I teach microbiology and feel the same way as Larry.
I think that it is a general problem for those of us that teach students that, besides our exams, have to answer questions written by others: GRE, MCAT, USMLE or other exams.
I believe that we should prepare our students for what we think (or we know) that is important for their professional life, but also we have the duty of preparing them for what those persons that write those exams consider is important.
Usually the topics are the same, but the approach is different. Since our students has to pass also those exams, I think that, besides the teaching that we consider is necessary for their professional life, we need to warn them about which specific topics and/or which specific approaches are explored in "third party" exams that our students need to pass. We can not change those exams, so, as we say in my country "we need to give the saints what the saints want"
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