Mediation of artifacts in behavioral research

An integrative artifact model is developed from a combination of role theory and McGuire's information-processing theory of social influence. The main extraneous sources of systematic error are reduced to three conjoint mediators, the end product of which determines the likelihood that a subject will positively or negatively react to demand characteristics. Conditions thought to affect the mediating variables are noted, and the practical advantage of this combinatory view is discussed as it applies to estimating the inferential validity of experimental findings in psychology.