Ceiling effect

This article describes the test theory effect. For use in pharmacology, see ceiling effect (pharmacology) .

The articles ceiling effect , floor effect (test procedure) and ceiling effect (pharmacology) thematically overlap. Help me to better differentiate or merge the articles (→  instructions ) . To do this, take part in the relevant redundancy discussion . Please remove this module only after the redundancy has been completely processed and do not forget to include the relevant entry on the redundancy discussion page{{ Done | 1 = ~~~~}}to mark. Zulu55 ( discussion ) 16:28, Jul 10, 2018 (CEST)

Ceiling effect ( English ceiling effect ) denotes a measurement error that is due to the exceeding of the measuring range. Its counterpart, a measurement error due to underflow of the measuring range is called ground effect ( english floor effect ).

example

If you put a letter that weighs over 100 grams or a package with several kilograms on a letter scale that shows a maximum of 100 grams, the scale always shows 100 grams, regardless of how heavy the item actually placed is.

Test theory

A good test determines the differences between the test objects, also at the "edges", ie with the very strong and very weak test participants. If a test is so simple that many test subjects achieve the optimal result (e.g. the highest possible number of points), although their performance capabilities are very different, it is called the ceiling effect . If, for example, an intelligence test is designed in such a way that it can no longer reliably measure the intelligence quotient (IQ) of a person above a certain limit, it is called the ceiling effect. As a rule, this limit is around 140: that is, filling in every question in the intelligence test correctly leads to an IQ of 140. The test cannot deliver an even better result, no matter how intelligent the test person really is.

• Example:

Given is a fictitious intelligence test whose creators claim to be able to reliably cover the intelligence quotient range from 50 to 150 IQ points. The test consists only of several mathematical subtests in which the test person is asked to continue given series of numbers according to logical criteria. The most demanding series of numbers may have the following form:

a) 1 2 3 4 5 (solution: 6)
b) 2 4 6 8 10 (solution: 12)
c) 3 6 9 12 15 (solution: 18) etc.

Since these tasks can presumably be solved correctly by many test participants, including those with lower intelligence, but since more intelligent test subjects should have no problems, a high number of points is likely to be achieved by almost all test subjects after working through all tasks. The test results of the most thus reach the "ceiling" (English. Ceiling ), and the desired significance damaged.

In the opposite case, if the test is so difficult so that many subjects zero or few points achieved, although their performance is different, it is called ground effect and floor effect .

literature

• Bortz & Döring (2005). Research methods and evaluation (p. 182). Heidelberg: Springer-Verlag. ISBN 3-540-41940-3

Individual evidence

1. ↑ Joachim Krauth: Test construction and test theory . Beltz Verlag 1995. ISBN 3-621-27286-0 .