Publications by dan
R is now the number two statistical computing program in scholarly use
WE THOUGHT IT WAS NUMBER ONE Robert Meunchen has done a rather in depth analysis of the popularity of various packages for statistical computation. More detail here. We were surprised to see that R has passed SAS for scholarly use. We were surprised because we assumed this would have happened years ago. Meunchen too predicted it would have happe...
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How many calories should you eat per day?
US GOVERNMENT GUIDELINES BY AGE, SEX, ACTIVITY LEVEL Click to enlarge At Decision Science News, we are always on the lookout for rules of thumb. Our colleague Justin Rao was thinking it would be useful to express calories as a percentage of daily calories. So instead of a coke being 150 calories, you could think of it as 7.5% of your daily calori...
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Heuristica: An R package for testing models of binary choice
CLASSIC HEURISTICS AND DATA SETS ALL IN ONE TIDY PACKAGE It just got a lot easier to simulate the performance of simple heuristics. Jean Whitmore, a software engineer at Google with a long history in modeling cognition, and Daniel Barkoczi, a postdoctoral fellow at the Max Planck Institute for Human Development, have created heuristica: an R pac...
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Turn your tough decisions into simple rules
FAST AND FRUGAL TREES R PACKAGE CREATES QUICK, ACCURATE DECISION TREES Fast and frugal trees allow you to make rapid decisions based on a few pieces of information. You can easily carry them out in your head. Surprisingly, the accuracy of these decisions rivals those made by gold-standard methods like logistic regression, especially when predict...
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How many digits into pi do you need to go to find your birthday?
FIND YOUR BIRTHDAY IN PI, IN THREE DIFFERENT FORMATS It was Pi Day (March 14, like 3/14, like 3.14, get it?) recently and Time Magazine did a fun interactive app in which you can find your birthday inside the digits of pi. However: 1) They only used one format of birthday, in which July 4th would be 704. But there are other ways to write July 4...
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Another rule of three, this one in statistics
SAMPLE UNTIL THE FIRST SUCCESS, PUT A CONFIDENCE INTERVAL ON P(SUCCESS) We wrote last week of Charles Darwin’s love of the “rule of three” which, according to Stigler “is simply the mathematical proposition that if a/b = c/d, then any three of a, b, c, and d suffice to determine the fourth.” We were surprised to learn this is called th...
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Counterintuitive probability problem of the day
TWO SHOT RUSSIAN ROULETTE WITH 2 BULLETS OR AN EQUAL CHANCE OF 1 or 3 BULLETS With p as the probability of dying on one shot, this figure shows how to get the probability of living through the game. Peter Ayton is giving a talk today at the London Judgement and Decision Making Seminar Imagine being obliged to play Russian roulette – twice (if ...
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Counterintuitive problem: Everyone in a room keeps giving dollars to random others. You’ll never guess what happens next.
SURPRISING POLICY EFFECTS http://www.decisionsciencenews.com/wp-content/uploads/2017/06/dollar_stacked.mp4 When we were giving a talk at the Department of Electrical Engineering and Computer Science at Northwestern we met Uri Wilensky, who shared with us a simulation he likes to assign. Imagine a room full of 100 people with 100 dollars each. Wi...
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Weighted population density
DENSITY THE AVERAGE PERSON EXPERIENCES CLICK TO ENLARGE In Alaska, there’s about one person for each square mile of land. You might picture a typical Alaskan not being able to see the next house. But it’s not that way of course. Most of Alaska is uninhabited. People have crowded into a few areas. The average Alaskan experiences a populatio...
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Five kinds of weather you’ll meet in America
K-MEANS CLUSTERING, A WORKHORSE OF DATA SCIENCE AND MACHINE LEARNING CLICK TO ENLARGE The USA is a large country. How different are people’s experiences of the weather depending on where they live? To look into this question, we downloaded high temperature data for over 1,300 airport weather stations in the contiguous USA for every day for fiv...
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