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@misc{cogprints824, volume = {103}, number = {1}, title = {Significance Test or Effect Size?}, author = {Siu L. Chow}, year = {1988}, pages = {105--110}, journal = {Psychological Bulletin}, keywords = {statistical significance, effect size, statistical power, meta-analysis, modus tollens, the sample-size problem, theeffect-size problem, the substantive-significance problem, theory corroboration}, url = {http://cogprints.org/824/}, abstract = {I describe and question the argument that in psychological research, the significance test should be replaced (or, at least, supplemented) by a more informative index (viz., effect size or statistical power) in the case of theory-corroboration experimentation because it has been made on the basis of some debatable assumptions about the rationale of scientific investigation. The rationale of theory-corroboration experimentation requires nothing more than a binary decision about the relation between two variables. This binary decision supplies the minor premise for the syllogism implicated when a theory is being tested. Some metatheoretical considerations reveal that the magnitude of the effect-size estimate is not a satisfactory alternative to the significance test.} }