What Your Friends Don’t Know About You

Wednesday, June 30, 2010
By Sharad Goel
Elephants and donkeys. This is a little subtle!

How well do you know your friends' political views? According to recent work by Winter Mason, Duncan Watts, and myself, you probably don't know them as well as you think. In particular, we found that when friends disagree on a political issue, they are unaware of that disagreement about 60% of... »

Extremely Weak Cryptography: Rot13 for Numbers

Monday, May 31, 2010
By dreeves
Two people giving (encrypted) arguments about various encryption schemes. ... 'EBG13 vf terng!' ... 'Double ROT13 is better!'

The idea of rot13 is to obscure text, for example, to prevent spoilers. It's not meant to be cryptographically secure but simply to make sure that only people who are sure they want to read something will read it. "It's handy when coordinating by text message when one or both parties are about to get... »

Misleading Means: On Drugs and Discrimination

Friday, April 30, 2010
By Sharad Goel

How do you estimate the prevalence of HIV among drug addicts? In a perfect (though somewhat Orwellian) world you'd have a giant list of all drug users, and you'd randomly select a subset of them to test for HIV. Alas, the world is messy, and we're left to less rigorous methods, for example... »


Yes, You Are (Maybe) Overconfident

Wednesday, March 31, 2010
By dreeves

218 of you took our calibration quiz, not counting the 10% of submissions that had to be thrown out for not being complete or giving ranges with the min greater than the max or other sanity check failures.... »

Are You Overconfident?

Sunday, February 28, 2010
By dreeves
How to estimate the distance from the Earth to the Moon, if you're the Little Prince.

We shall now find out if Messy Matters readers are smarter than Mechanical Turkers. For each of the questions below, provide a numerical range that you are 90% sure contains the correct answer. In particular, if you... »

Prediction Without Markets

Thursday, January 14, 2010
By Sharad Goel
photo-finish

In the 2008 Summer Olympics Usain Bolt ran 100 meters in 9.69 seconds, earning the gold medal and garnering the international attention that comes with being the "fastest man in the world." While... »