Definitions by Awesomedude8888

RTTM 

Regression Towards The Mean

In statistics, regression toward the mean (RTTM for short) is the phenomenon that if a variable is extreme on its first measurement, it will tend to be closer to the average on its second measurement—and, paradoxically, if it is extreme on its second measurement, it will tend to have been closer to the average on its first.

RTTM by Awesomedude8888 December 18, 2014