andrewvs

Snap Judgements Part Two: Beauty in the Classroom

Nearly a decade ago, Daniel Hamermesh of UT-Austin and Jeff Biddle of Michigan State found that, for a variety of occupations, a person's looks have a statistically significant effect on earnings ("Beauty and the Labor Market," American Economic Review, December 1994, pp. 1174-94). Other things constant, people with above average looks earned about 5 percent more than people with average looks, and those with below average looks earned about 5 percent less. Whether this premium results from higher work productivity remains an open question. Perhaps better looking people have the confidence to seek better paid positions or people who earn more can afford better grooming, a more stylish wardrobe, and more cosmetic surgery and dental work.

As a way of moving closer to the productivity question, Hamermesh and Amy Parker, an undergraduate economics major at UT-Austin, wanted to find out whether an instructor's looks affects course evaluations. Their sample consisted of student evaluations of 463 undergraduate courses taught by 94 instructors at UT-Austin during the academic years 2000-2002. Underlying the sample were 16,957 completed evaluations.

To develop an index of beauty, the authors asked six undergraduates (three males and three females) to independently score each instructor's looks based on a photograph. Beauty scores were fairly consistent across the six judges. The authors also gathered other information about each instructor, including gender, tenure-track status, minority status, and whether educated in an English-speaking country.

They found, after adjusting for other factors, that courses taught by instructors judged as better looking received significantly higher course ratings. On a scale from 1.0 to 5.0, with 5.0 the best, evaluations ranged from 3.5 for the least attractive instructors up to 4.5 for the best looking, other things constant. The average course evaluation was 4.0. The effect was robust and found within university departments and even within particular courses. Compared to female instructors, male instructors gained more of a premium for good looks and more of a penalty for bad looks.

The question remains whether beauty makes instructors more productive in the classroom—say, because students pay closer attention or because better looking teachers are more self confident—or whether students are simply giving those with irrelevant beauty characteristics higher evaluations.

Average evaluations were lower for females, minority faculty, non-native English speakers, and tenure trackers. The higher evaluations for non-tenure trackers may at first seem surprising but these instructors are often selected specifically because of their teaching ability. "Beauty in the Classroom: Professors' Pulchritude and Putative Pedagogical Productivity" (July 2003) is available here.

William A. McEachern
Issue 25, Fall 2003
The Teaching Economist

Snap Judgements Can Be Accurate

What would you think of having someone evaluate your teaching after viewing just a soundless 10-second video clip of you in action? Sounds crazy, doesn't it? But researchers who study "thin slices" of expressive behavior have found that viewers of such a clip feel quite comfortable making an evaluation based on such limited input. What's more, this instant analysis tracks relatively well with students' end-of-term evaluations.

According to Harvard researchers Nalini Ambady and Robert Rosenthal, observers who were presented with a 10-second silent video clip of a teacher in a classroom setting had no difficulty rating the teacher on a 15-item checklist of personality traits. Moreover, when the clip was cut to five seconds, the ratings were the same, and they remained the same when the clip was cut to two seconds of videotape. These findings were discussed by Malcolm Gladwell in The New Yorker, ("The New-Boys Network," 5/29/2000, pp. 68-86). Gladwell admits that this all seems unbelievable, but after he viewed both ten second clips and two seconds clips, he concluded that the eight seconds were "superfluous," noting that "anything beyond the first flash of insight is unnecessary"(p. 70). Snap judgments are just that—made in a snap.

The next step for Ambady and Rosenthal was to compare these snap judgments with judgements of teacher effectiveness based on end-of-term student evaluations. The correlation was relatively high. As Gladwell concludes, "A person watching a two-second silent video clip of a teacher he has never met will reach conclusions about how good that teacher is that are very similar to those of a student who sits in the teacher's class for an entire semester" (p. 70).

William A. McEachern
Issue 19, Fall 2000
The Teaching Economist

Why Rubbing a Boo Boo Makes It Feel Better

Have you ever banged your shin on a coffee table? Boy, that smarts.

Your first reaction, after cursing under your breath, was probably to rub it. Rubbing doesn't make the pain go away, but it sure makes it feel a lot better.

So what's going on?

Here's a story that helps to explain the phenomenon: I once banged my shin (just like we've been talking about), and a brother of mine who shall remain nameless (Chris), decided to help me out. He said, "Come here Drew—this will make you forget your shin." and WHAM!, he punched me in the arm. This new "distration" did indeed cause me to forget my shin.

Well, the same happens when you rub a boo boo. You have two sets of neurons competing for the attention of your brain: pain fibers and touch fibers. When you bang your shin, the pain fibers signal the brain. Rubbing the affected area causes the touch fibers to send another signal to the brain, and as a by-product, reduce the amount of pain signal that gets through.

That's the short, slightly inaccurate, explanation. For the full scoop, click on the three icons below. They will expand to slides that describe the actual mechanism.

Normal Condition

Pain

Pain and Touch

What to Say When a Child Asks, "What is this?"

New research suggests that when children ask "what is this?" they may seek an object’s function

Normally, adults assume that when children ask, "What is this?" in reference to an object, they are seeking merely a name—some kind of label to help differentiate the elements of their rapidly burgeoning universes. However, a new study explored the possibility that children posing such a question might actually be seeking the object’s function, not simply its name. These findings by Swarthmore College researchers Deborah Kemler Nelson, Morghan Holt and Louisa Chan Egan will be published in the June issue of Psychological Science, a journal of the American Psychological Society.

The study separated two-, three-, and four-year-olds into two groups, and allowed the children in each group to inquire about unfamiliar artifacts. In one group, questions were answered with the name of the object; in the other, its function was provided. Regardless of age, children were inclined to follow up with supplemental questions about an object when they were told only its name. However, the children given thorough, functional information seemed more satisfied with the response.

Moreover, children receiving only an object’s name tended to rephrase their questions over the course of the session in an attempt to elicit more functional information. These results suggest that young children might well be interested in and capable of distinguishing objects by more than just a superficial classification.

So, when your child asks, "What is this?", answer by saying something like:
     That's a spoon; we use it to help us eat food.
     This is a shovel; we use it to pick up and move dirt.
     This is tape; we use it to stick paper together.
Extra credit: Say, "Let me show you." and then model the object's use.

It's my opinion that it is never too early to begin this kind of interaction. (Don't wait for a child to have the expressive vocabulary to ask the questions. As you go through your daily routines, explain what you are doing and why.) Even when you think your child is too young and doesn't have the vocabulary to understand everything you are saying, they are picking up a great deal of information. Plus, you become better at providing descriptions with practice.

Tabletop Illusion

Here's a fun little illusion. The tabletops in the image below are the same size. Do you believe it?

First, rotate the table on the right counterclockwise about 75 degrees:

...then erase the legs:

And now you see, the tabletops really are the same size. Even though you know this now, when you look back at the top picture, they still look like they are unequal—that's one of the characteristics of an illusion—explaining it doesn't make it go away.

Here's an example where this illusion could work to your advantage or disadvantage:

Resistance to Effective Instruction

It is hard to keep your humor when you accept the fact that you invested 25 years in developing methods that can help your nation out of the educational abyss into which it is racing. You made these methods inexpensive. You made them clear. You helped illustrate their worth. You made them attractive. Yet they are ignored or rejected because of popular myth and bigotry. I should have known this when I started in 1965, but I didn't. I went blissfully on even though others tried to warn me.
Ogden Lindsley, 1992

For information about Dr. Lindsley's approach to teaching—Precision Teaching—go here.

For another extremely effective approach to instruction, read about Direct Instruction here.

And for another angle, read about the Personalized System of Instruction here.

What is the difference between these programs and the programs commonly used in classrooms today? These programs have been proven time and time again—using rigorous scientific methods—to work. Unfortunately, these programs don't conform to what many teachers want to do. But shouldn't teachers do whatever is necessary to product effective, efficient, and humane instruction? What would happen to patients if doctors wanted to practice medicine according to their personal preferences, irrespective of the results of research studies. What would you think if a doctor treated you using outdated practices, but defended themselves by saying, "This is the way I've been doing it for 40 years. I know what works."

The next time somebody tells you about how effective their instruction is, or how good a course or program is, I suggest that you ask them, "How do you know? Can you show me data?"

Launch of Open Learning Support

I am pleased to announce a website that I and the rest of the OSLO Research Group at Utah State University have been working on for the last several months.

Open Learning Support (OLS) is an online forum where students from around the world can help each other learn from the course materials MIT has made available online, for free, through their OpenCourseWare initiative.

During this pilot test phase, OLS online forums are available for seven of MIT's courses. In a few months (or sooner depending upon demand) we will open up forums for all 700 of the courses available.

Attention Experiment

This experiment is going to knock your socks off.

This is a test of attention. This is not an IQ test so don't feel bad if you have some difficulty with the task—it's supposed to be difficult.

Your job is to count the number of times the white-shirted team passes the ball back and forth between themselves. As you can see from the image below, there is also a black-shirted team passing another ball back and forth—that's what makes the task difficult—they get in the way sometimes and make it difficult to keep an accurate count. (I've highlighted the target ball in red in the image below to help you out. It won't be highlighted in the actual movie, though.)

Here's what to do:
     1. Read through all the directions, then come back and click here to go to experimenter's page.
     2. Wait for a moment while the movie loads.
     3. Click on the arrow at the left hand bottom corner of the movie to start playing it. The movie only lasts for about 30 seconds, but the white team starts passing the ball right away so make sure to pay attention.
     4. After the movie is finished, come back to this page and click on the Continue reading "Attention Experiment" link below. No cheating now—you only get one chance to count the passes. ; )

Color Constancy Illusion

This is one of my favorite illusions because, as is the case in all illusions, knowing how the phenomenon works doesn't change your perception of it. (When I first saw this illusion, I had to open the images in Photoshop and sample the colors to prove to myself that they really were the same.)

Figure 1: Area 1 and area 2 are the same shade of gray.

Figure 2: Area A and area B are the same shade of gray.

Figure 3: The blue tiles on top of the left cube and the yellow tiles on top of the right cube are the same shade of gray. That's right, gray.

For an explanation of the phenomenon, and to see other illusions of this type, go here or here.

If you thought this was interesting, look for an upcoming post on Edwin Land's color experiments. He was able to produce full-color images using only one (1) color filter. Forget Red/Green/Blue—how about just Red?