This is even more of a problem with multiple choice tests.
Cieling flooring effects epidemiology.
Ceiling effects and floor effects both limit the range of data reported by the instrument reducing variability in the gathered data.
There is very little variance because the floor of your test is too high.
Sometimes floor and ceiling effects are referred to as lower and upper censoring.
A ceiling effect can occur with questionnaires standardized tests or other measurements used in research studies.
A floor effect is when most of your subjects score near the bottom.
Psychology definition of floor effect.
The inability of a test to measure or discriminate below a certain point usually because its items are too difficult.
The mini mental state examination mmse is the most widely used cognitive test both in clinical settings and in epidemiological studies.
In layperson terms your questions are too hard for the group you are testing.
In some fields biology physiology etc the ceiling effect refers to the point at which an independent variable no longer has an effect on a dependent variable when a kind of saturation has been reached e g the phenomenon in which a drug reaches its maximum effect so that increasing the drug dosage does not increase its effectiveness baker 2004.
However correcting its score for education may create ceiling effects when used for poorly educated people and floor effects for those with higher education.
In most longitudinal epidemiological studies these floor and ceiling effects are ignored.
The term ceiling effect is a measurement limitation that occurs when the highest possible score or close to the highest score on a test or measurement instrument is reached thereby decreasing the likelihood that the testing instrument has accurately measured the intended domain.