In the first case, there is a strong upward-sloping relationship between X and Y; in the second case, no apparent relationship; in the third case, a strong downward-sloping relationship. Note the ...

Depressed people send more email. They spend more time on Gchat. Researchers at the Missouri University of Science and Technology recently assessed some college students for signs of melancholia then ...

Correlation doesn't imply causation. You've probably heard that before. It's a true statement that's important in statistical analysis—if more tall people own cats, that doesn't mean that cats cause ...