What Regression toward mean is
Regression toward the mean is a statistical phenomenon that occurs when extreme values of a random variable are followed by values that are closer to the mean. The phenomenon is also known as regression to the mean.
For example, if a student scores extremely high on a test, there is a greater chance that their score on the next test will be lower than their first score.
Steps for “Regression Toward the Mean”:
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Identify a population to be studied.
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Select a random sample from the population and measure the variable of interest.
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Measure the same variable of interest in the same sample at a later time (or measure the same variable in a different sample).
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Compare the two sets of results and look for evidence of regression toward the mean.
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Analyze the results to determine if the regression is statistically significant.
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Interpret the results and draw conclusions.
Examples
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A basketball player who makes an unusually high number of shots in a single game will likely shoot a lower number of shots in subsequent games.
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A stock that experiences a sudden surge in price will likely fall back toward its original price range.
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A student who scores unusually well on a test may not perform as well on the next test.