The blog The Wrong Stuff has some excellent interviews about how people deal with errors or mistakes. It reminded me of a book I wanted to read, but I never got past the book review. Basically, most experts are no better at predicting the future than a drunken monkey. This quote reminds me of why I hate talking to smart people:

“Most people tend to dismiss new information that doesn’t fit with what they already believe. Tetlock found that his experts used a double standard: they were much tougher in assessing the validity of information that undercut their theory than they were in crediting information that supported it.”

Smart people are better at rationalizing and defending their opinions no matter how inane. That doesn’t mean they aren’t useful. Smart people excel at analyzing subjects for which they have no personal interest, i.e. the price of wheat futures. If they could learn to apply that same Vulcan logic to the things they care about, they would realize that most of what they believe rests on a very shaky foundation. Then they might be more open to information that changes their mind. Or they might, like me, wallow in a tar pit of indecisiveness.

I wrote a little script to grab the weather forecasts from the Weather Underground for the past 6 months. I want to know how good their predictions are from 1 to 4 days out. Unfortunately, it’s been 20 years since I last looked at a statistics book. For my first pass through I computed the root mean square error of predicting the daily high temperature. For predictions 1, 2, 3, and 4 days away, the values are 2.9, 3.4, 4.9 and 5.0 respectively. That doesn’t sound so good to me, but I need to figure out what other metrics to squeeze out of this. For example, I want to compare their forecasts against a simple prediction algorithm: the weather will be just like today. I also want to know the reliability of a forecast, which I think is the confidence interval (95% confidence the prediction is within 1 degree of the actual temperature). Finally, I have the data on conditions and precipitation to chew on, too. For now, the error residuals are looking pretty bleak. You should always carry an umbrella.

I first ran across Dunbar’s number in The Tipping Point. Robin Dunbar estimates that humans can maintain, on average, a group size of 150 people. Beyond that people are more like strangers. The Economist interviewed Cameron Marlow from Facebook, who has analyzed how people socialize on Facebook. The numbers are better summarized here. The key point is that people appear to have a close relationship (measured by regular communication) with only 5% of their overall group. The average number of friends on Facebook is 120 (though a big range), but people regularly communicate with only around 6 of those people (women have a few more close friends than men). I don’t think you can equate Facebook friends with Dunbar’s number because it’s too easy to add random people and never think about them again. But it’s interesting that the average is around the same.

I just got my vision tested 6 months after LASIK surgery. I think my prescription lenses were at -2.5 diopters and almost no astigmatism. I can now see at 20/15, which is better than “normal” vision. No dryness, itching, halos or blurred vision. There was mild dryness for 2 months after surgery, but one morning it completely disappeared. When I was researching LASIK I ran across lots of scary stories on anti-LASIK forums. But the studies I read showed a very high success rate, especially for my simple prescription. The neighborhood kids no longer call me a “four-eyed, skinny dork”. Now it’s just “skinny dork”, but I’m working on that.

Apparently other men have poor aim and miss the toilet. How can they miss such a large target? They simply aren’t paying attention. By putting a small picture of a housefly (why this?) on the inside of a urinal, “spillage” declined 80%. (how did they measure spillage? and what poor soul got that job?) Someone should sell a sticker that can be placed inside a normal toilet bowl and market it on Oprah. You’re certain to make millions. Incidentally, toilets are designed poorly because there’s still the issue of splashing. That Dyson vacuum cleaner should work on this.

This snippet from a story on cell phones was impressive. People can be quite clever.

Ugandans are using prepaid airtime as a way of transferring money from place to place, something that’s especially important to those who do not use banks. Someone working in Kampala, for instance, who wishes to send the equivalent of $5 back to his mother in a village will buy a $5 prepaid airtime card, but rather than entering the code into his own phone, he will call the village phone operator (“phone ladies” often run their businesses from small kiosks) and read the code to her. She then uses the airtime for her phone and completes the transaction by giving the man’s mother the money, minus a small commission.

From NYTimes story:

In a series of studies in the 1970s and ’80s, psychologists at the University of Washington put more than 300 students into a study room outfitted like a bar with mirrors, music and a stretch of polished pine. The researchers served alcoholic drinks, most often icy vodka tonics, to some of the students and nonalcoholic ones, usually icy tonic water, to others. The drinks looked and tasted the same, and the students typically drank five in an hour or two.

The studies found that people who thought they were drinking alcohol behaved exactly as aggressively, or as affectionately, or as merrily as they expected to when drunk. “No significant difference between those who got alcohol and those who didn’t,” Alan Marlatt, the senior author, said. “Their behavior was totally determined by their expectations of how they would behave.”

In a repeat of the session performed for a coming documentary, one participant insisted that she could not have been drinking because alcohol always made her flush.

“We told her that, yes, in fact she was drinking it,” Dr. Marlatt said. “She immediately flushed.”