Internal Validity

Definition: An indicator of the extent to which a study’s findings are representative of the true effect in the population of interest and not due to research confounds, such as methodological shortcomings. In other words, whether the observed evidence or covariation between the independent (predictor) and dependent (criterion) variables can be taken as a bona fide relationship and not a spurious effect owing to uncontrolled aspects of the study’s set up. Since it involves the quality of the study itself, internal validity is a priority for scientific research.

Alternative definition: In Psychometrics, the degree of evidence that confirms the internal structure of a psychometric test as compatible with the structure of a psychological construct.

Related terms: External validity, Validity

Related term to alternative definition: Construct validity

Reference: Campbell and Stanley (1966)

Drafted and Reviewed by: Annalise A. LaPlume, Helena Hartmann, Oscar Lecuona, Meng Liu, Sam Parsons, Graham Reid, Flávio Azevedo

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