First, an announcement: the YouTube link in the previous announcement now works. It is here.
I just finished teaching a cookbook lab in our general biology course at Southeastern Oklahoma State University. The lab was an experiment in which students measured the effects of enzyme concentration, temperature, and pH on the activity of amylase. We measured amylase activity by roughly quantifying glucose production: glucose turns Benedict’s solution (which is blue because of copper) into an orange or red color. This can actually be exciting, because you have to boil the solution to make the color appear, and it is always fun to watch students using clamps to manipulate little test tubes in beakers of boiling water. The broken glass container got some use today.
Like the other instructors, I told the students to follow the cookbook instructions. The instructions told them exactly what to put in each of their eight test tubes, and which pipettes to use, and to put the amylase in last (since that starts the reaction); where to put the tubes for incubation; how to use the Benedict’s solution; how to score the results. Cookbook all the way so far.
I participated in the Botany 2014 conference of the Botanical Society of America in Boise, Idaho, is always the high point of my year in those years that I attend—and that’s saying something. If you read this blog regularly, you know I have lots of interesting activities. But the people at the Botany conferences are so enthusiastic, knowledgeable, and professional, that the conference reinvigorates me. The conference is so welcoming to students; even undergraduates present their results, and as often as not their papers are as good as those that us older people present. I especially admire my fellow participants in the Teaching Section, where we meet to exchange ideas about how to teach botany and related subjects (like general biology).
It is popular for educators to disparage “cookbook labs” in biology education. Even the term used for it is a put-down. While I admire the professional creativity of the anti-cookbookers, I have to stick up just a little for the cookbook lab in which we tell the students exactly what to do at each step.
The main reason for having cookbook labs is that our students, at least, have little or no experience with basic scientific manipulation, such as how to use a pipette, or why they should not mix pipettes up (amylase with starch, acid with base, etc.). Even our best students are worried they might do something wrong, and they often do, by simply not reading the instructions. There are always a few who put amylase in the control tube. If we just gave them the materials and background information and let them work it out themselves, many of them would get very confused. We have extra materials so that if they screw up, they can start over. A fifteen minute incubation in a two-hour lab is not too difficult to redo if necessary. But without cookbook instructions, the groups of students would have to start over so many times that we could not, with our limited staff, make up and clean up enough materials, especially since our labs are scheduled back-to-back-to-back. And with every seat in the lab occupied, there may be twelve groups of students. And if each group screws up in a different way, how is one instructor (or two, if we are lucky) help each of them out of their confusion? I had so much work on my hands anyway that I did not notice that the boiling water beakers dried out and started smelling like melted glass. I got to them just in time.
Therefore in my experience, cookbook labs aren’t so bad. Cookbooks aren’t so bad. Some things you can throw together while cooking—I never consult a cookbook—but other things you have to be careful about doing just the right way, and published advice from good cooks becomes very valuable in those cases. Cookbooks even have their own style of grammar that is universally accepted, with its reliance on the imperative mood and omission of articles (“bring water to rolling boil”), a grammar also used in lab manuals. To me, the alternative is chaos.
But here is where we depart from a cookbook mentality. Once the students have their row of test tubes lined up, from blue (the control in which the Benedict’s solution had nothing to react with) to orange or red, they had to think about the results for themselves. They had to test hypotheses about the effects of amylase concentration, temperature, and pH (independent variables) on enzyme activity (dependent variable) and then graph it. Here, there were no explicit instructions, and nearly everybody got it wrong at first. But they got it creatively wrong, made the corrections, and understood (in most cases) what had happened. Here is where the real education occurred. I will agree with my anti-cookbook colleagues that we should not tell the students what to think about their results. If their results were “wrong,” we had them make note of it but not to change their results to make them fit the expectations, and they lose no points for getting wrong results, so long as they understand them.
In a future week we will have another cookbook lab: look at the slide, draw it, and label it, without really thinking about what the parts do. Now, that is the kind of cookbook lab I really don’t like. But I didn't write the lab book for the course.
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