ceiling effect
A measurement limitation where participants score at or near the maximum possible score, preventing detection of further improvement.
Full Definition
A ceiling effect occurs when a measurement instrument fails to detect differences or changes in the construct being measured because participants score at or near the top of the scale. In psychiatric research, this can happen when patients have mild symptoms and score near the maximum 'healthy' end of rating scales, or when treatments are so effective that further improvement cannot be measured. Ceiling effects limit the ability to detect treatment differences, assess dose-response relationships, or identify patients who might benefit from additional interventions. This phenomenon is particularly problematic in studies of high-functioning patients or maintenance treatments.
Usage
Usage note: Hyphenate when used as an adjective; contrast with floor effect in research contexts.
In Context
- "The rating scale showed a ceiling effect in the high-functioning patient group." — Psychometric analysis
- "Ceiling effects limited the ability to detect differences between active treatments." — Statistical limitations