For example, if a test is too easy, the phenomenon of most individuals scoring generally higher is called the ceiling effect. The phenomenon in which most individuals score generally lower because the test is too difficult is known as the floor effect.

"Leather Mareion effect"

Legend has it that on the ancient Greek island of Cyprus, there was a young prince named Leather Mareion, who loved art, and through his own efforts, finally sculpted a statue of a goddess. For his own masterpiece, he loved it, all day long with affectionate gaze at him. After a long time, the goddess finally came back to life and was happy to be his wife. This story contains a very profound philosophy: expectation is a kind of power, the power of this expectation is called by psychologists "leather Mareon effect".