Month: March 2010

Teaching: What I Learned Last Semester

Seth Roberts1 Comment

Andrew Gelman’s thoughts about teaching led me to mull over what I learned last semester from teaching at Tsinghua. I taught two classes: a freshman seminar that covered a wide range of psychology research; and a class for graduate students about R.

Some things worked well:

1. In the freshman seminar, one of the assignments was to design a Mindless-Eating-type experiment. (Mindless Eating by Brian Wansink was one of the reading assignments.) One of the students designed a really good experiment in which people on different buses get different treatments. She happened to be a senior applying for graduate school and her work on that assignment helped me write a really strong letter of recommendation for her.

2. I graded the students on their comments on the reading and set the bar very high to get a full score (3 out of 3): they had to say something that interested me. A fair number managed to do this. The bar wasn’t too high.

3. I had lunch with all the students in the seminar (about 5 per week). The students seemed to like it. I certainly did.

4. There were classroom debates about which paper was the best (one week) or the worst (another week). They got everyone involved, was far less passive than listening to me talk, and gave them practice speaking English.

But there was plenty of room for improvement:

1. Students in the seminar were frustrated by the vague criterion (“interest me”). Toward the end I posted the comments that got the full score and that seemed to help.

2. In the seminar it was hard to get feedback about how well I was being understood. The best I could do was pass out slips of paper and have the students write down what percentage of what I said they understood. More immediate feedback (e.g., when I used a too-difficult word) would have been better.

3. In the R class I hoped the students would analyze their own data. This was too hard for quite a few of them. In the future I’ll give them a data set.

4. One student dropped the R class because my English was hard to understand.

5. In the seminar, some students (freshmen) complained that other (older) students, whose English was better, talked too much. They had a point and I should try calling on people randomly. I also should try to get general feedback after each class (e.g., “tell me one thing you liked and one thing you didn’t like about today’s class”).

6. In spite of my constant complaint that professors treat all of their students alike (e.g., all students get the same assignment) when they aren’t all alike — they differ substantially in what they’re good at, for example — I pretty much did the same thing.

7. I should have at least tried to learn my students’ Chinese names.

Why Do We Dislike Short-Range Repetition?

Seth Roberts6 Comments

Here’s something I wrote a few days ago:

In graduate school, I studied experimental psychology. I wanted to learn how to do experiments. The best way to learn is to do, I thought, so I started doing self-experiments in addition to my regular research (with rats). One thing I studied was my acne. My dermatologist had prescribed tetracycline and benzoyl peroxide. In a few months, my self-experiments showed that tetracycline didn’t work and benzoyl peroxide did work — the opposite of what I originally believed.

Emphasis added. I wanted to write “the opposite of what I originally thought” but the earlier use of thought made me use believed instead. Avoidance of this sort of repetition is standard practice. It’s even important scientifically. The linguist David Stuart made a big advance in understanding ancient Mayan when he realized that different symbols mean the same thing. The different symbols appeared in the same block of text, like my thought and believed.

My question is: Why? What’s the evolutionary reason? Maybe it’s part of a push toward novelty, so that nobody says, “Today I went to the store. Today I went to the store.” Or maybe it’s a way of pushing us to make distinctions, invent new words, and learn new words. It pushes us to make distinctions because it pushed me away from lazily writing ” . . . thought . . . thought”.

One reason this interests me is my interpretation of why we like repeated decorative elements. Many sorts of decoration involved repeated elements — identical things or pictures placed side by side. I believe we like this sort of thing so that we will place similar things side by side. When we place them side by side it’s easy to notice small differences that would otherwise be hard to see. Noticing small differences makes us connoisseurs. Connoisseurs are important economically because they are willing to pay more for finely-made stuff. They support cutting-edge artisans.

The invent-new-words explanation strikes me as the most plausible. First we do what the Mayans did: invent new words that mean exactly the same thing as the old words, purely to avoid short-range repetition. As the words get older, their meanings drift independently and they start to mean slightly different things (such as job and profession). Thereby the language does a better job of keeping up with technical/economic progress, which keeps generating new things that need new names.

One Man Vs. All Education Professors

Seth Roberts16 Comments

According to a recent New York article about Rupert Murdoch, Robert Thomson, one of Murdoch’s top editors,

thinks most [journalists] are liberals overly concerned with writing stories that will impress other liberal journalists and win prizes in journalism competitions.

Well, yes. Not everyone is a liberal, of course, but basically everyone wants to impress their colleagues. Scientists have an amusing spin on this: They call it “peer review.” The amusing part is that somehow no one else’s opinion should matter. (E.g., all journals must be peer-reviewed.) Scientists get away with this bizarre view of economics (thinking someone should pay you and get nothing in return) perhaps because it is indeed difficult to assess the quality of this or that bit of science if you’re not in the field and because science has produced huge benefits for the rest of us in the past.

As I said, this is just human nature. As far as I can tell, professors act this way — try to impress colleagues — in every academic department. In schools of education, the result is this:

Amy Treadwell . . . received her master’s degree in education from DePaul University, a small private university in Chicago. . . . But when she walked into her first job, teaching first graders on the city’s South Side, she discovered a major shortcoming: She had no idea how to teach children to read. “I was certified and stamped with a mark of approval, and I couldn’t teach them the one thing they most needed to know how to do,” she told me.

It’s no secret that many schools of education do a poor job of training their students to teach — which is nominally one of their main goals. I am just repeating what Veblen said long ago.

What’s new is this: One man, Doug Lemov, working mostly alone, has figured out how to make people better teachers. One man. Not a professor. Did he build on the work of others? No, he started from scratch. He’s made a list of about 50 techniques. They are teachable. He gives workshops about them. As far as I can tell from this magazine article, Lemov has done a better job of figuring out how to train teachers than all the education professors in the world put together. If you arrived on earth from outer space, and didn’t understand human nature, you’d think this couldn’t possibly be true, but apparently it is. It’s like something out of a comic book.

Assorted Links

Seth Roberts2 Comments
  • the I Practice My Own Methods Developed From Self-Experimentation group. Which, when this was written, had one member. She has Parkinson’s Disease and found that yoga helps. “I started watching yoga on tv because [my husband] had the tv on and he likes to watch attractive women expressing themselves physically.”
  • umami basics. “Maturation increases the content of umami.”
  • reasonable talk about addiction by Gabor Mate, a Vancouver doctor. “The first time I took heroin, it felt like a warm soft hug.” Mate says his addiction to classical CDs was like a heroin addiction. Sure, you laugh, he says, and goes on to say that one weekend he spent $8,000 on classical CDs, that his wife could tell when he’d been classical-CD shopping, and he once neglected a woman in labor (he was an obstetrician) because he was buying classical CDs. “In effect, our system punishes and prosecutes people for having been abused in the first place.”

Thanks to Bob Levinson.