Encyclopedia of Clinical Neuropsychology

2018 Edition
| Editors: Jeffrey S. Kreutzer, John DeLuca, Bruce Caplan

Multiple Comparisons

  • Michael FranzenEmail author
Reference work entry
DOI: https://doi.org/10.1007/978-3-319-57111-9_1217

Definition

Multiple comparisons involve the situation when more than one statistical test of significance is conducted on a single set of data (Hu 1999). Statistical tests estimate the probability that the observed difference could occur on the basis of chance findings. If p < 0.05, the difference found is likely to be seen only five times if the experiment is repeated 100 times. If more than one comparison is completed, the experiment-wide error rate changes. In these instances, the probability level is inflated, and the researcher may wish to control for experiment-wide error with a mathematical correction. For example, a study may investigate the effect of age on memory, abstract problem-solving, verbal fluency, spatial analysis, and attention. Having multiple comparisons raises the probability that a spurious significant difference may be found for one or more of the variables.

Current Knowledge

For a priori comparisons, that is, for comparisons that are planned on the basis of...

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References

  1. Hu, J. C. (1999). Multiple comparison: Theory and methods. Boca Raton: CRC Press.Google Scholar
  2. Klockars, A. J., & Sax, G. (1986). Multiple comparisons. Newbury Park: Sage.CrossRefGoogle Scholar

Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Allegheny General HospitalPittsburghUSA