---
title: Ceiling effect
description: "| In OM this refers to most people choosing the maximum possible score on an item or a scale. This leaves no scope to record differences above this ceiling. A floor effect is the opposite: most or all people scoring…"
url: "https://www.psyctc.org/psyctc/glossary2/ceiling-effect/"
updated: "2021-11-10"
category: All OM book glossary entries
---

# Ceiling effect

| In OM this refers to most people choosing the maximum possible score on an item or a scale. This leaves no scope to record differences above this ceiling. A floor effect is the opposite: most or all people scoring on the lowest possible score. Both limit the Variance of scores. A ceiling effect can make an item, or, much more seriously, a whole OM score insensitive to differences and change above the “ceiling” so an item like “I have felt unhappy” may be fine to detect differences in general well-being but won’t distinguish between those with mild low mood and those in a deeply despairing state. |
| --- |

#### Detail

Bit more about diagnosing it, impact and about IRT?

#### Try also ...

[Floor effect](https://www.psyctc.org/psyctc/glossary2/floor-and-ceiling-effects/)
[Variance](https://www.psyctc.org/psyctc/glossary2/variance/)
[Range](https://www.psyctc.org/psyctc/glossary2/range/)
Range constriction
[Bias](https://www.psyctc.org/psyctc/glossary2/bias/)
Validity & invalidity
Item Response Theory

#### Chapters

Nothing here yet!

#### Further reading

Nothing here yet!

#### Online tools

Possible simulation and perhaps diagnostics for ceiling and floor effects.