Placebo, Hawthorne, and Other Artifact Controls

Abstract

This article reports the results of mail surveys of educational researchers who either did or did not employ specially treated control groups (STCGs). Whereas some consistency in actual practice was found, the surveys revealed confusion among researchers over the definition of and relationship between both sources of artifact and placebo, Hawthorne, and attention-placebo controls. The survey data indicated the need for research assessing the effects of various artifact control practices and for a conceptual model of artifact and their controls in educational research.