Blog Archives

Which chart is better?

August 10, 2010
By
Which chart is better?

CHART CRITICS, GRAPHICS CURMUDGEONS, COME ONE COME ALL Once upon a time there was this graph (graph 1). Andrew Gelman went all graphics curmudgeon on it, calling it an “ugly, sloppy bit of data graphics“, so it became this graph (graph 2). Now the question is, which is better: graph 2 or graph 3? Please

Read more »

The counterfactual GPS!

July 23, 2010
By
The counterfactual GPS!

WHAT IF YOUR GPS TOLD YOU WHAT WOULD HAVE HAPPENED IF YOU HAD TAKEN THE OTHER ROUTE? Not long ago, your Decision Science News editor was planning a trip to a book group meeting along with another member. The monthly book group takes place in Cove Neck Long Island, about an hour East of Manhattan.

Read more »

Navigate the Bermuda Triangle of Mediation Analysis

July 6, 2010
By
Navigate the Bermuda Triangle of Mediation Analysis

MYTHS AND TRUTHS ABOUT AN OFTEN-USED, LITTLE-UNDERSTOOD STATISTICAL PROCEDURE If you go to a consumer research conference, you will hear tales of how experiments have undergone particular statistical rites: the attainment of the elusive crossover interaction, the demonstration of full mediation through Baron and Kenny’s sacred procedure, and so on. DSN has nothing against any

Read more »

Maps without map packages

July 1, 2010
By
Maps without map packages

LATITUDE + LONGITUDE + OVERPLOTTING FIX = MAPS Decision Science News is always learning stuff from colleague, physicist, mathlete, and all-around computer whiz Jake Hofman. Today, it was a quick and clean way to make nice maps in R without using any map packages: just plot the latitude and longitude of your data points (e.g.

Read more »

Baseball, basketball, and (not) getting better as time marches on

June 2, 2010
By
Baseball, basketball, and (not) getting better as time marches on

PROS ARE NOT GETTING BETTER AT FREE THROWS Rick Larrick recently told Decision Science News that baseball players have been getting better over the years in a couple ways. First, home runs and strikeouts have increased. The careless or clueless reader might note that this is curious, for from the batter’s perspective home runs are

Read more »

Tuesday’s child is full of probability puzzles

May 28, 2010
By
Tuesday’s child is full of probability puzzles

COUNTERINTUITIVE PROBLEM, INTUITIVE REPRESENTATION Blog posts about counterintuitive probability problems generate lots of opinions with a high probability. Andrew Gelman and readers have been having a lot of fun with the following probability problem: I have two children. One is a boy born on a Tuesday. What is the probability I have two boys? The

Read more »

You won, but how much was luck and how much was skill?

May 4, 2010
By
You won, but how much was luck and how much was skill?

In baseball, what are the chances the winner will win again against the same opponent the very next day?

Read more »

Tipping heuristics

April 28, 2010
By
Tipping heuristics

INCREDIBLY SIMPLE CALCULATIONS MADE SIMPLE Yes, we all know how to calculate 15% or 20% exactly, but it’s fun to use tipping heuristics and even more fun to make crowded graphs of how they compare to each other. (Sorry for the junky chart. Open for suggestions, in the words of Tom Waits.) Here are a

Read more »

Get at least 12 observations before making a confidence interval?

April 14, 2010
By
Get at least 12 observations before making a confidence interval?

How many observations should you have before constructing a confidence interval?

Read more »

Score with scoring rules

July 21, 2009
By
Score with scoring rules

INCENTIVES TO STATE PROBABILITIES OF BELIEF TRUTHFULLY We have all been there. You are running an experiment in which you would like participants to tell you what they believe. In particular, you’d like them to tell you what they believe to be the probability that an event will occur. Normally, you would ask them. But

Read more »