The feasibility of informed pretests in attenuating response-shift bias

Abstract

Response-shift bias has been shown to contaminate self-reported pretest/posttest evaluations of various interventions. To eliminate the detrimental effects of response shifts, retrospective measures have been employed as substitutes for the traditional self-reported pretest. Informed pretests, wherein subjects are provided information about the construct being measured prior to completing the pretest self-report, are considered in the present studies as an alternative method to retrospective pretests in reducing response-shift effects. In Study 1 subjects were given a 20-minute presentation on assertiveness, which failed to significantly improve the accuracy of self-reported assertiveness. Other procedural influences hypothesized to improve self-report accuracy-previous experience with the objective measure of assertiveness and previous completion of the self-report measure-also were not related to increased self-report accuracy. In a second study, information about interviewing skills was provided at pretest using behaviorally anchored rating scales to participants in a workshop on interviewing skills. Response-shift bias was not attenuated by providing subjects with information about interviewing prior to the intervention. Change measures which employed retrospective pretest measures demonstrated somewhat higher (although nonsignificant) validity coefficients than measures of change utilizing informed pretest data.