Friday, 30 July 2010

The dramatic effects of kindergarten education: A controlled (!) experiment

The NY Times ("The Case for $320,000 Kindergarten Teachers", 27 July 2010) has just published an article about a very interesting controlled (!) experiment. The Harvard economists that conducted this unusual study (how many controlled experiments in education do you know about?) conclude that "a standout kindergarten teacher is worth about $320,000 a year. That’s the present value of the additional money that a full class of students can expect to earn over their careers. This estimate doesn’t take into account social gains, like better health and less crime."

If this is true, deciding on a kindergarten suddenly becomes a lot more significant that you may have imagined...

Some interesting excerpts:
How much do your kindergarten teacher and classmates affect the rest of your life?

Economists have generally thought that the answer was not much. Great teachers and early childhood programs can have a big short-term effect. But the impact tends to fade. By junior high and high school, children who had excellent early schooling do little better on tests than similar children who did not — which raises the demoralizing question of how much of a difference schools and teachers can make.
Just as in other studies, the Tennessee experiment found that some teachers were able to help students learn vastly more than other teachers. ... Students who had learned much more in kindergarten were more likely to go to college than students with otherwise similar backgrounds. Students who learned more were also less likely to become single parents. As adults, they were more likely to be saving for retirement. Perhaps most striking, they were earning more.

All else equal, they were making about an extra $100 a year at age 27 for every percentile they had moved up the test-score distribution over the course of kindergarten. A student who went from average to the 60th percentile — a typical jump for a 5-year-old with a good teacher — could expect to make about $1,000 more a year at age 27 than a student who remained at the average. Over time, the effect seems to grow, too.
The crucial problem the study had to solve was the old causation-correlation problem. Are children who do well on kindergarten tests destined to do better in life, based on who they are? Or are their teacher and classmates changing them?
The Tennessee experiment, known as Project Star, offered a chance to answer these questions because it randomly assigned students to a kindergarten class. As a result, the classes had fairly similar socioeconomic mixes of students and could be expected to perform similarly on the tests given at the end of kindergarten.

Yet they didn’t. Some classes did far better than others. The differences were too big to be explained by randomness. (Similarly, when the researchers looked at entering and exiting test scores in first, second and third grades, they found that some classes made much more progress than others.)

Class size — which was the impetus of Project Star — evidently played some role. Classes with 13 to 17 students did better than classes with 22 to 25. Peers also seem to matter. In classes with a somewhat higher average socioeconomic status, all the students tended to do a little better.

But neither of these factors came close to explaining the variation in class performance. So another cause seemed to be the explanation: teachers.

Some are highly effective. Some are not. And the differences can affect students for years to come.

Friday, 16 July 2010

Dirac: Elegance is more important than empirical fit

Scientific American has re-printed a 1963 article by Paul Dirac, The Evolution of the Physicist's Picture of Nature, in which he says: "It is more important to have beauty in one's equations than to have them fit experiment." The sentiment expressed here by Paul Dirac, the celebrated quantum physicist, isn't that surprising to those who recall Einstein's famous quote:
Reporter: What would you do if the measurements of bending starlight at the 1919 eclipse contradicted his general theory of relativity?

Einstein: Then I would feel sorry for the good Lord. The theory is correct.
In all, the article provides an enjoyable glimpse into the mind of a great scientist, showing that scientists do not always think and operate the way we expect them.

Saturday, 10 July 2010

Michael Hawley: Sheet music piracy is okay (

DAVID POGUE: "No Easy Answers in the Copyright Debate" ( 8 July 2010)

Michael Hawley, formerly of the M.I.T. Media Lab, now a digital-media researcher, award-winning pianist and polymath, ... wrote to explain why he thinks sheet-music pirating is O.K., or even necessary:
I play the piano. Over the years, I have collected 15,000 piano scores in PDF form, covering about 400 years of classical keyboard works.

It's like lint in the drier of the Internet. Much of it is not available anywhere for purchase, or even findable in libraries for circulation. Max Reger's arrangement for two pianos of Wagner's overture, for instance? Well, the Max Reger Institute in Karlsruhe, Germany has a copy...

The last classical sheet music store in New York, Patelson's, went out of business recently. The recession finished them off. It was THE place to go to buy piano music. When I was in high school, I used to go there for hard-to-find scores by Granados or Medtner, and then hit the Carnegie Deli for some pastrami. Amazing, isn't it? New York City doesn't have an independent store that sells classical music scores.

Fortunately, over the last ten or fifteen years, amateur pianists have been scanning the contents of their grandmother's piano benches, and... voilĂ . A million monkeys typing don't get you Shakespeare, but a million monkeys scanning -- that makes a dent. I began collecting this stuff as a hobby. One day, I looked at my pile of music score bits. In those days, 15 gigabytes was most of my hard drive. But it was all there. All of Bach. All of Scriabin. All of Rachmaninoff.

At the Van Cliburn piano competition, a couple years ago, I gave tiny thumb drives to some of the winners and said, "Enjoy." Each thumb drive was smaller than my pinky but contained was the whole 15 GB trove. It blew their minds. Basically, every significant piano piece is in the pile.

What happened is, the classical piano sheet music publishing world plotzed a long time ago. But thanks to the monkeys, a lot of DNA has been preserved and is more available now than ever before. The monkeys aren't as well organized as the Wikipedia minions, but someday they will be.

When the publishers, composers, music stores have long since gone out of business, when the libraries don't have the stuff, the internet quickly becomes the Sargasso sea for catching this stuff. Not saying that your songwriter friend's points aren't completely valid -- of course they are. As slippery as digital rights are, the fact is that digital publishing probably gives people more ways to make more money and reach far wider audiences than the paper-based music publishing racket ever did.

But copyright, like the people who originate the material and the industries that promulgate it, has a lifespan. I think the classical piano sheet music world gives a glimpse of the end state -- out of the ashes of the music business, comes the rebirth of the musician business (as John Perry Barlow once said). It also, more importantly, shows what happens when a society does a poor, random job of preserving their cultural heritage to nurture future generations.

Generally, I side with the teenagers.

Saturday, 3 July 2010

Fair Trade

From: Fair Trade and the Food Movement - Freakonomics Blog -
The problem with Fair Trade coffee is that as the program scales up, the alternative market ethics it wants to sustain collapse. Inevitably, the Fair Trade market becomes subject to the same laws that drive the conventional commodities market. When the price of coffee drops, the appeal of Fair Trade’s price support lures growers into the cooperatives that sell coffee under the Fair Trade label. As poor growers rush into Fair Trade agreements, the supply of Fair Trade coffee rises. Protected by the price floor, the Fair Trade coffee remains inflated despite flagging demand. What Fair Trade importers thus end up doing with the excess Fair Trade coffee is dumping it—upwards of 75 percent of it!—on the conventional market.