Garbage In Garbage Out: if your data is flawed, any conclusions you draw from it will be, too.

 

It is Latin for "with this, therefore because of this," a logical fallacy which involves incorrectly inferring a causation from a correlation. You should always remember—correlation does not imply causation.

 

One which doesn't appear in the plot of two other variables, but could have an effect on both. It is also sometimes referred to as a confounding variable.