Two statisticians

Two statisticians are out hunting when one of them sees a duck. The first takes aim and shoots, but the bullet goes sailing past six inches too high. The second statistician also takes aim and shoots, but this time the bullet goes sailing past six inches too low. The two statisticians then give one another high fives and exclaim, “Got him!”

Worth a thousand words

A good graphic can tell a story, bring a lump to the throat, even change policies. Here are three of history’s best. See also Edward Tufte’s book The Visual Display of Quantitative Information. (Via)

Statistics Made Visual

(…)Each image portrays a specific quantity of something: fifteen million sheets of office paper (five minutes of paper use); 106,000 aluminum cans (thirty seconds of can consumption) and so on. My hope is that images representing these quantities might have a different effect than the raw numbers alone, such as we find daily in articles and books. Statistics can feel abstract and anesthetizing, making it difficult to connect with and make meaning of 3.6 million SUV sales in one year, for example, or 2.3 million Americans in prison, or 426,000 cell phones retired every day. This project visually examines these vast and bizarre measures of our society, in large intricately detailed prints assembled from thousands of smaller photographs. (…)

Pictures by Chris Jordan.

Correlation does not imply causation

Correlation does not imply causation is a phrase used in the sciences and statistics to emphasize that correlation between two variables does not imply there is a cause-and-effect relationship between the two. Its converse, correlation implies causation, is a logical fallacy by which two events that occur together are prematurely claimed to have a cause-and-effect relationship. It is also known as cum hoc ergo propter hoc (Latin for “with this, therefore because of this”) and false cause.

An episode of The Simpsons (Season 7, “Much Apu About Nothing”) serves as a good example of this principle. Springfield had just spent millions of dollars creating a highly sophisticated “Bear Patrol” in response to the sighting of a single bear the week before.

Homer: Not a bear in sight. The “Bear Patrol” is working like a charm!
Lisa: That’s specious reasoning, Dad.
Homer: [uncomprehendingly] Thanks, honey.
Lisa: By your logic, I could claim that this rock keeps tigers away.
Homer: Hmm. How does it work?
Lisa: It doesn’t work. (pause) It’s just a stupid rock!
Homer: Uh-huh.
Lisa: But I don’t see any tigers around, do you?
Homer: (pause) Lisa, I want to buy your rock.

(source)