Ceiling effects and floor effects both limit the range of data reported by the instrument reducing variability in the gathered data.
The floor effect explained.
A floor effect is when most of your subjects score near the bottom.
This lower limit is known as the floor.
Let s talk about floor and ceiling effects for a minute.
Learn what a ceiling effect is and how to eliminate it using the overall experience rating developed and.
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.
Common scales used in visitor studies and evaluation often suffer from ceiling effects.
This could be hiding a possible effect of the independent variable the variable being manipulated.
There is very little variance because the floor of your test is too high.
In layperson terms your questions are too hard for the group you are testing.
Limited variability in the data gathered on one variable may reduce the power of statistics on correlations between that variable and another variable.
This is even more of a problem with multiple choice tests.
In research a floor effect aka basement effect is when measurements of the dependent variable the variable exposed to the independent variable and then measured result in very low scores on the measurement scale.