Let s talk about floor and ceiling effects for a minute.
Floor and ceiling effet.
In layperson terms your questions are too hard for the group you are testing.
In statistics a floor effect also known as a basement effect arises when a data gathering instrument has a lower limit to the data values it can reliably specify.
The other scale attenuation effect is the ceiling effect floor effects are occasionally encountered in psychological testing.
There is very little variance because the floor of your test is too high.
However there is variation among reported promis pi floor effects that appears to depend on patient population.
Ceiling effects and floor effects both limit the range of data reported by the instrument reducing variability in the gathered data.
This is even more of a problem with multiple choice tests.
In fact only 1 study noted a ceiling effect of 3 4 7 5.
Limited variability in the data gathered on one variable may reduce the power of statistics on correlations between that variable and another variable.
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.
Psychology definition of floor effect.
A floor effect is when most of your subjects score near the bottom.