Correlations and the reason why we do studies

Just a few correlations to keep in mind when you hear that some event is “statistically” correlated to another.

The correlation coefficient ranges from −1 to 1. A value of 1 implies that a linear equation describes the relationship between X and Y perfectly, with all data points lying on a line for which Y increases as X increases. A value of −1 implies that all data points lie on a line for which Y decreases as X increases. A value of 0 implies that there is no linear correlation between the variables

• –1.0 A perfect negative relationship

• –0.70. A strong negative relationship

• –0.50. A moderate negative relationship

• –0.30. A weak negative relationship

• 0.0 No linear relationship

• +0.30. A weak positive relationship

• +0.50. A moderate positive relationship

• +0.70. A strong positive relationship

• +1.0 A perfect positive relationship

So let’s have a look at some very strong correlations:

Math doctorates vs Uranium (Correlation r=0.952257)

Japanese passenger cars vs Suicides (Correlation r=0.935701)

Drowning vs Power Generation (Correlation r=0.901179)

US Oil Imports vs Drivers Killed (Correlation r=0.954509)

See other Spurious Correlations at tylervigen.com