A retest often shows a subject’s score moving toward the mean; this phenomenon is known as what?

A retest often shows a subject’s score moving toward the mean; this phenomenon is known as what?

• A. Regression Effect
• B. Practice Effect
• C. Ceiling Effect
• D. Floor Effect

Answer: (A)

Scores that are unusually high or low on a first test tend to move closer to the average on a retest because of regression to the mean. This happens because the observed score combines the person's true ability with random error from that testing moment. If the initial score was unusually high due to favorable random factors, the next measurement is likely to reflect less of that random boost, bringing the score closer to the population mean. Conversely, an unusually low first score may rise on the next attempt for the same reason. This is distinct from a practice effect, where performance improves simply from familiarity with the test, and from ceiling or floor effects, which limit how high or low scores can go due to test design rather than a general shift toward the mean.

Scores that are unusually high or low on a first test tend to move closer to the average on a retest because of regression to the mean. This happens because the observed score combines the person's true ability with random error from that testing moment. If the initial score was unusually high due to favorable random factors, the next measurement is likely to reflect less of that random boost, bringing the score closer to the population mean. Conversely, an unusually low first score may rise on the next attempt for the same reason. This is distinct from a practice effect, where performance improves simply from familiarity with the test, and from ceiling or floor effects, which limit how high or low scores can go due to test design rather than a general shift toward the mean.