This illustrates the problem with so much of standard instruction, especially in undergraduate mathematics. The ideas have become so polished over decades if not centuries, and we who teach this material understand its nuances so thoroughly, that what we present glides easily past our students without opportunity to grasp its true complexities. For learning to take place, students must engage and wrestle with the concepts we want them to understand.
Cartoon courtesy of brownsharpie.courtneygibbons.org
licensed under the Creative Commons BY-NC-SA 3.0 license
licensed under the Creative Commons BY-NC-SA 3.0 license
I am not advocating confusion for confusion’s sake. As Courtney Gibbon’s cartoon illustrates, a polished lecture can also be very confusing, and not in a good way. Confusion is most productive when it provides a focus for personal investigation. An example of positive confusion is the cognitive dissonance produced when student expectations confront convincing evidence that they are wrong. My prime example of this is George Pólya’s Let Us Teach Guessing (see my Launchings column Pólya's Art of Guessing).
I like to think of this as “gritty” mathematics rather than confusing mathematics. One of my favorite examples from personal experience was a Topics in Real Analysis course that I taught in Spring 1997 using Thomas Hawkins’ doctoral dissertation, Lebesgue’s Theory of Integration: Its Origins and Development, as the text. My experience teaching that course laid the foundation for my textbook A Radical Approach to Lebesgue’s Theory of Integration. Back in 1998, I wrote a paper about this experience, “True Grit in Real Analysis.” I never published it, but I still like it, and as a New Year’s gift to readers, I offer a link to that paper.
[1] Kolowich, S. Confuse Students to Help Them Learn. The Chronicle of Higher Education. September 5, 2014. Available at http://chronicle.com/article/Confuse-Students-to-Help-Them/148385/