The College Board is in the process of rewriting the curriculum for science courses to make them more inquiry-based. This has prompted me to revisit my process for converting conventional “cookbook” labs to inquiry format.
Note:Â since writing this post, I have subsequently written a more detailed manual for Developing Inquiry-Based Laboratory Experiments in High School Chemistry.
My own experience leads me to agree with the article by Cindy E. Hmelo-Silver, Ravit Golan Duncan, and Clark A. Chinn [“Scaffolding and Achievement in Problem-Based and Inquiry Learning: A Response to Kirschner, Sweller, and Clark (2006), Educational Psychologist 42(2), pp. 99-107″]. During the 2005-06 school year, I tried an experiment to teach experimental design by having my AP kids do a lab they remembered from Chem I without a written procedure. The experiment (mine) was successful—the kids got a lot out of the process, and because they already knew in their minds what they needed to do, there was minimal added cognitive load for understanding the experiment itself.
Over the course of that school year, I gradually changed my paradigm for how I administered labs, learning quite a bit in the process about how much information and scaffolding kids need in order to actually internalize the experiment and relate it to what we’re doing on the white board and in the homework/on tests.
What I do currently is:
- I teach the concepts in detail before doing the experiment. (Otherwise, the students don’t have enough mental reference points to learn much from the experiment.)
- I give the students a written objective and “plan” (High-level description of the experimental procedure. For example, the plan for a titration lab might be:
- Make a solution of KHP with known concentration.
- Use the KHP solution to titrate a solution of NaOH to determine the exact concentration.
- Use the standardized NaOH to determine the concentration of an acid.
- The day before the experiment, I go over the experiment, talking through the detailed procedure and demonstrating key parts of it. In the ensuing class discussion, we talk about what data they need to collect. Early in the year, we construct a data table in this class discussion. As the year progresses, they gradually learn to construct the data table on their own. Also, if the experiment involves new lab skills (such as using a pipet bulb or adjusting the stopcock on a buret), I allow a few minutes for them to practice.
- On the day of the experiment, they walk into the lab in which I’ve set out any reagents that they need. They find everything else in the lab, set up their apparatus, and do the experiment.
- I spend the entire experiment moving from group to group, answering questions and helping them think through what they need to do if they get stuck.
- After the experiment, we have a brief (10-15 minute) class discussion about what they need to calculate (going back to the original objective) and how to proceed with the calculations.
I’ve found that after each experiment, all of my students can tell me (in their own words) what they did, how well it worked, and how it relates to the topics we’re studying.
Left to my own devices, I would probably describe what I do as Problem-Based Learning (PBL), but because Inquiry-Based Learning (IL) is the current buzzword of choice, and because the lines between PBL and IL are so unclear, I more often call it IL.
Some proponents of IL (including my former department head) have criticized what I do, claiming that it’s too teacher-directed to be true “scientific inquiry”. However, having tried those kinds of “true” IL experiments and activities (as well as traditional “cookbook” experiments and activities), I’ve had far superior results with what I described above.
Also, given what the test development committee were saying about the course changes at the AP Annual Conference, it sounds like what what I’ve described above fits within their notion of “inquiry-based experiments”. It teaches the skills required for the kinds of data analysis and error analysis that the committee said would have an increased presence on the exam, and it gives them a basis to be able to understand and answer the kinds of “what if” questions that the CB likes to ask. I also like it because it lets me continue using the labs that I have already chosen, taught, and debugged. It’s also easy to apply to a new cookbook-style experiment that I find and decide I like.
Originally posted to the ap-chem discussion list.
