What is meant by the "ceiling effect" in testing?

The term "ceiling effect" refers to a phenomenon where a test measures abilities or performance levels that are too easy for participants, resulting in a significant number of individuals achieving high scores. This saturation indicates that the test may not be sensitive enough to capture variations in performance among those at the upper end of the scale. In such cases, the highest scores mask any potential improvements or differences that may be present, limiting the test's ability to discriminate between the highest-performing individuals.

This effect can be particularly relevant in assessments of senior fitness, where a test designed with a lower difficulty level might lead to a large group of participants scoring near the maximum, ultimately making it difficult to detect true improvements in fitness or abilities over time.