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main effect

main effect A main effect is the effect of one independent variable considered across, or averaged over, all levels of the other variable or variables in a study.

A main effect is the effect of one independent variable considered across, or averaged over, all levels of the other variable or variables in a study. For example, it can describe the overall difference linked to one factor while ignoring how that difference may vary across another factor.

Also see

Sources

Drafting source: Online Statistics Education, version 2 (David M. Lane, project leader). Version 2; publisher statement snapshot 2026-10-18; SHA-256 0dcad9ee85f61f9e2bb24d26279de155ac749164ea4da2a3bffeabcf9ea471a6. “Main Effect” (main_effect.html).
public-domain-US · Definition uses new wording; original source retains its stated licence. · Source snapshot SHA-256: 21d8a9609dd1de710e2fa1b75a5abb833d11ff305dba4aa770933de2dce8bb6e

These citations identify the drafting sources. 2/2 independent reader passes against the pinned source packet. The drafter does not count as a reader. Source institutions do not endorse this dictionary.

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PsychTerms (psychterms.org), CC BY 4.0, version 1. “main effect.” Development preview.

Version 1 · SHA-256: 80f1b855e37ca4e5d280e2af5051e08418acaa76a0c6d5f275e2073f891ec258

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