The Teacher Who Made Mistakes on Purpose

Gilbert Strang would do a version of this too: appearing to work through problems on the fly and asking the audience for help, when of course he had come up with the problems himself and made them readily solvable to illustrate the concept he was teaching.

You can see instances of this in his last lecture in 2023.

https://www.youtube.com/watch?v=lUUte2o2Sn8

A professor I had in college had an anecdote about how his first publication was an open problem he accidentally solved in the process of doing his homework and he only found out long after when the professor cited it as [him] (unpublished).

He also seemed to, precisely once every semester, assign a problem among the homework problems that was, as written, an open problem in the field, only to, a couple days before the deadline, send out a clarification apologizing.

Having been around there a couple years, I always suspected that these two things were not unrelated.

Early on in high school we had one of the sports coaches substitute for a science teacher for a few months. The sub gave us a bad formula, and I spent a while on getting her to correct it. She pushed back, so I even wrote a very small paper showing how the formula she gave us didn't make sense because the value would have to have certain upper bounds, the formula would have to have a certain "shape" to it, etc. It was somewhat rewarding to care about the concept enough to do this, but it made the sub cry, and several of my classmates were angry and annoyed at me.

I think this article, even if it was true, downplays the social penalty that the kids who speak up might pay.

This is very 1990s chain-email glurge story.

I had a teacher that routinely did this.

I hated it.

The issue is that, at least for me, I'm madly trying to capture in my notes whatever it is the teacher was presenting. Then, on "step 15" we get the "Oh, did anyone notice this on Step 3?" and then they'd erase the board and we'd start again.

I never felt it was an interesting technique, especially early on, when, again, at least for me, I'm just trying to absorb everything. I don't know enough to separate the wheat from the chaff, and still barely understand what I'm doing. Many times one can succeed by blindly following a process without understanding, and over time that understanding arrives, aided by repetition and application of the examples.

Folks learn differently with different ways. This was not an effective teaching technique for me.

This is an engagement boosting technique that is popular on social media too, a.k.a. comment baiting. It was commonly used in 2003 on TikTok.

If I recall correctly, Sal Khan from Khan Academy fame has suggested homework and school work should be flipped—video lessons at home and student and teacher interaction on the math problems at school. This has some of that flavor.

While this approach can engage some students, it risks confusing others and potentially eroding trust. A balanced method might involve planned "mistakes" alongside clear, accurate instruction.

To be clear, this appears to be a work of fiction?

Are people taking this to be a real life account, and if so whats the basis for that. I'm not seeing anything on this blog to indicate otherwise.

Do this too often and you risk losing the trust of your students, however.

I immediately thought of this substitute teacher who was mispronouncing all of the students names during row call: https://www.youtube.com/watch?v=DoNLC1UALSI

It seem like Cunningham's Law https://en.m.wiktionary.org/wiki/Cunningham%27s_Law also works in real life.

A bit tangential but, when a teacher asks if anyone knows x, he/she doesn't want the nerd wiseguy who actually knows to answer, he wants someone who is unsure to answer so that everyone can participate in the learning experience.

Cunningham's Law: "the best way to get the right answer on the Internet is not to ask a question, it's to post the wrong answer"

I teach math to smart nerdy high schoolers. I do this. It's great! Fun for everyone :)

A professor once taught me: If you want your presentation to be remembered, don't make it too perfect. Add some (obvious) errors, mispellings etc. to keep the audience awake.

Great article.

It reminds me of another anecdote, regarding a university professor who told his students that he would deliberately include one falsehood in each lecture, and the students were charged with listening carefully and identifying the 'mistake' in each class.

For the very last class in the course, the professor trolled his students by not including any mistake.

Reminds me of https://xkcd.com/386/

I have worked as a teacher. I have tried this. This doesn't work. Period.