Regression to the mean: what it is and how to deal with it
pubmed.ncbi.nlm.nih.gov › 15333621Background: Regression to the mean (RTM) is a statistical phenomenon that can make natural variation in repeated data look like real change. It happens when unusually large or small measurements tend to be followed by measurements that are closer to the mean. Methods: We give some examples of the phenomenon, and discuss methods to overcome it at the design and analysis stages of a study.
Regression toward the mean - Wikipedia
en.wikipedia.org › wiki › Regression_toward_the_meanIn statistics, regression toward the mean is a concept that refers to the simple fact that if one sample of a random variable is extreme, the next sampling of the same random variable is likely to be closer to its mean. Furthermore, when many random variables are sampled and the most extreme results are intentionally picked out, it refers to the fact that a second sampling of these picked-out variables will result in "less extreme" results, closer to the initial mean of all of the variables. Mat