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Philosopher Generalizes Beyond Experience

Janet pointed me to a post at the Philosopher’s Playground about doing away with laboratory courses in the science curriculum. Steve Gimbel, the philosopher doing the playing, teaches at Gettysburg College. He argues that the lab portions of science classes cause non-science majors to avoid those courses and not enroll in any science class not required for graduation. If science courses consisted of more theory and less labs (by theory he means lecture, and, by choosing that word, he indicates he doesn’t have much experience in non-physics science courses where the lectures consist of more than ‘theory’) non-science-majors would be more likely to take science courses, according to Gimbel.

Additionally, Gimbel points out that many experiments conducted in teaching labs lead to results that are inconsistent with the course material. That’s not because the course material is wrong, but because the experimental techniques employed in teaching labs are faulty. The combination of the time required and the crappy results lead Gimbel to conclude that we can do away with teaching labs. Both Gimbel and Janet are philosophers of science, specializing in physics and chemistry, respectively. As a biologist with way too much experience teaching undergraduate lab classes, I felt it necessary to make a few points defending their existence.

First off, we must make an important distinction between courses required for non-science majors and those required of science majors. Even though Gimbel tries to focus his argument on courses for non-science majors, he brings up some points that apply to both the groups. Gimbel claims that “students have a three to four hour chunk of their weekly schedule carved out in order to take any science class.” I seem to remember my chemistry lab classes taking three to four hours, but many biology labs are only booked for a far more manageable two hour block. Some of them, however, do require students to come in outside of their scheduled lab times to care for live organisms (ie, collect virgin Drosophila or maintain some plants), but a two hour block is far less obtrusive in one’s schedule than a three or four hour commitment.

But Gimbel claims the real costs are on the faculty side, where faculty must “teach the lecture course and a couple sections of the associated lab,” meaning they have fulfilled their teaching requirement with a single course. Instructors for non-lab courses, on the other hand, are required to teach multiple courses, increasing what Gimbel calls their “curricular footprints”. While this may be true for small colleges like Gettysburg, it doesn’t hold at large research institutions.

At larger schools, courses with lab components are quite balkanized. They are divided into the lecture component, which is handled by a faculty member or team taught by a couple instructors, and the laboratory section. The laboratory sections are usually taught by graduate students or advanced undergrads. The grad students get valuable teaching experience (and financial support) that would otherwise be unavailable without laboratory courses. Most faculty members are not overwhelmed by the lab portion of the course because they do not deal with the labs — that is left to teaching assistants and laboratory coordinators. This issue is more of a difference between small colleges and large universities than lab and non-lab courses.

What about the benefits of lab courses from a student’s perspective? I do acknowledge that the experiments performed in lab courses are clumsy and of poor quality. But, as I emphasize to my students, the purpose of a lab exercise is not to do amazing experiments, but to gain an understanding of how science is done. As I have stated previously, one does not understand science without understanding the hypothetico-deductive method. Yes, there is more to science than this simple approach, but it provides basic framework for understanding what scientists do.

And therein lies the value of laboratory courses. The students should perform experiments in which they develop hypotheses, test those hypotheses, and analyze their results relative to their hypotheses. I’ve previously argued that science courses should be organized around the scientific method rather than the memorization of facts or the practical application of the knowledge. A laboratory component that emphasizes the scientific method would complement such a lecture perfectly. This approach applies to both courses for majors and non-majors.

There are two more benefits of laboratory courses at large universities that I would like to point out. First, lab courses which require students to write up their results both emphasize the communication component of the scientific process and provide the students with an opportunity to write. Underclassmen don’t spend much time writing in their science lectures. They take exams, which consist of multiple choice and short answer questions, but the lecture courses are usually devoid of writing requirements. It’s my opinion that being able to write clearly is one of the most important skills for a student to develop. Forcing students to write and have their writing evaluated will, hopefully, improve the quality of their communication skills.

In addition to writing lab reports, lab and recitation components of courses at large universities allow students to interact with instructors or TAs in smaller classes. These lab sections usually contain about 20 students, whereas lectures may have hundreds of students. A good lab course will reinforce material covered in lecture and allow students to ask questions about the material in a more welcoming environment. This is often the only chance science majors get to take a small class at large universities in their first couple of years.

While there are drawbacks to lab courses, they are essential to a good education in the life sciences. As Gimbel points out, grading lab reports is hard (much more difficult and time consuming than grading exams), but, if a lab course is designed correctly, it will teach students important concepts that they would otherwise miss in a lecture only curriculum. This is especially true at large universities which have gigantic lecture sessions. In the end, the difference in conclusions (between Gimbel and me) may simply be the result of differences between small colleges and large universities and between the physical sciences and the life sciences.

Comments

  1. #1 razib
    March 29, 2007

    jesus, this post rocked dude, it rocked!

  2. #2 chet snicker
    March 29, 2007

    good show sir, good show! a lab course is after all the ‘university of life’ for anyone with an inclination toward the natural sciences.

  3. #3 Ponder Stibbons
    March 29, 2007

    I doubt that labs teach anything substantial in terms or writing skills. Any decent college should mandate that students take a certain number of writing-based classes anyway. Except in small liberal arts colleges, lab reports are usually graded by TAs, many of whom are foreign and probably have worse writing skills than the native English-speaking students. In fact, in my physics labs, 80% of the lab TAs were foreigners who often had trouble explaining lab procedures to us. This is because most of the English-speaking grad students were shunted to run discussion sessions for the theory courses, leaving mostly foreigners to be lab TAs.

    I get the impression that labs in the biological sciences are more well implemented than labs in the physical sciences. I had to take biological science courses to meet core requirements, and I found that the bio labs were structured to be much more friendly to actually stimulating students to construct hypotheses and attempt to deduce conclusions from results. In contrast, my physics labs were almost entirely concerned with checking if the results of the experiment fitted with some predetermined equation that we were simply told was true. We rarely had the chance to form our own hypotheses. It is ironic that phyiscs labs were, given their uselessness, still so much more time-demanding than biology labs. My quantum mechanics lab had two sessions of four hours each a week.

    I don’t think providing grad students with financial support or teaching experience is a good reason to hold lab courses, since it’s actually the undergrads who are paying for the grad students’ financial support (lab courses cost more than non-lab courses). Undergrad tuition shouldn’t be decided by the educational and financial demands of graduate students, but by how far the extra tuition would improve the education of the undergrads themselves.

    In short, I think labs are in theory educationally useful, but given the widespread poor implementation of labs in the physical sciences, I’m not convinced they add much to the education of physical science majors. Every physics major I know admits that they learn a lot more about how real science is done from their extra-curricular research projects carried out under the supervision of individual professors than from labs. There is, in my experience, almost no resemblance between the two experiences — I wish I could have spent all that time in the labs on my independent research instead. I am not at all convinced that physics labs help to expose students to what real scientific research is like. There are no lab manuals in real research. A lot of beginning students are put off being scientists because they think real research is something like their negative lab experiences (at my college, about a third of prospective physics majors switch to math for this reason). This is not healthy if we want to train more scientists.

  4. #4 j-smith
    March 30, 2007

    I can’t say I really agree with all that you are arguing for here. I’ve got a more detailed response on my blog:
    Why I skip labs
    but I would like to make one point in line with what Ponder Stibbons is saying. Higher education in the U.S. is declining is significant ways, and we might do well to recognized that. Through that recognition we might reasonably come to the conclusion that an alternative strategy for science education must be considered.

  5. #5 RPM
    March 30, 2007

    My point is that any introductory course in science should emphasize science as a process, not science as a collection of facts. Having the students perform experiments in a lab setting is a good way to do this. I think we all pretty much agree that lab courses done right are good. But a lot of people have had bad experiences in lab courses, so they see them as a waste of time.

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