SECTION 5.4:
What are floor and ceiling effects in outcome measurement?
Table 5.4: Description of Floor and Ceiling Effects
| Measurement Property | Description |
|---|---|
| Floor effect | Floor effect occurs when responses on a measure, questionnaire or scale cluster at the more negative health state end of scale. For instance, if the scale were administered a second time, there would be no room to detect any possible deterioration in health, even if it had occurred. |
| Ceiling effect | Ceiling effect occurs when responses on a measure or questionnaire cluster at the more positive health state end of the scale. This means that if the scale were administered a second time, there would be no room to detect any possible improvements in health, even if they had occurred. |