regression toward the mean

Regression toward the mean refers to the statistical tendency where extreme measurements or outcomes tend to be closer to the average upon subsequent measurement. For example, if someone performs exceptionally well or poorly on one occasion, their next performance is likely to be closer to their typical or average level. This occurs because extreme results often include some random factors or fluctuations, and over time, these tend to balance out, leading to more typical outcomes. It is an important concept in understanding variability and preventing overinterpretation of single, extraordinary results.