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 ...

There’s an old saying that goes, “figures don’t lie, but liars can figure.” But sometimes even the figures can spin a confusing story. That’s why I’ve always appreciated the power of understanding ...

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 ...