手法を比較

	Free-Choice Dissonance Paradigm	Cover Story Deception
分野	社会心理学	社会心理学
系統	Process / pipeline	Process / pipeline
提唱年	1956	1959
提唱者	Jack Brehm	Classic experimental social psychology
種類	Experimental paradigm for post-decisional dissonance	Methodological design controlling participant expectations
原典	Brehm, J. W. (1956). Postdecision changes in the desirability of alternatives. Journal of Abnormal and Social Psychology, 52(3), 384-389.	Festinger, L., & Carlsmith, J. M. (1959). Cognitive consequences of forced compliance. Journal of Abnormal and Social Psychology, 58(2), 203-210.
別名	Free-Choice Paradigm, Post-Decisional Dissonance Paradigm, Spreading of Alternatives Paradigm	Deception Design, Cover Story Method, Experimental Deception
関連	3	3
概要	The free-choice paradigm, introduced by Jack Brehm in 1956, measures post-decisional dissonance through the phenomenon of spreading of alternatives. Participants first rate the desirability of a set of items, then choose between two options that they had rated as roughly equally attractive, and finally re-rate all the items. Because the chosen option has some unattractive features and the rejected option has some attractive ones, a difficult choice between similar alternatives creates dissonance; participants reduce it by enhancing their evaluation of the chosen option and devaluing the rejected one. This 'spreading' of the two alternatives' desirability after the decision is the paradigm's signature measure and a key demonstration that choices not only reflect preferences but also shape them. The paradigm became a standard tool for studying decision-induced attitude change, alongside the induced compliance procedure.	Cover story and deception design is the methodological practice of concealing a study's true purpose behind a plausible false rationale so that participants behave spontaneously rather than in line with what they think the experimenter wants. Because people who guess a study's hypothesis may consciously or unconsciously alter their behavior -- the problem of demand characteristics -- social psychologists often present a cover story that misdirects attention, embed the real dependent measure within an apparently unrelated task, and, when necessary, use additional deceptions such as confederates or false feedback. This approach made possible many of the field's classic findings on conformity, obedience, helping, and dissonance, where awareness of the true question would have destroyed the phenomenon. Deception carries serious ethical obligations, requiring justification, minimization of harm, suspicion probing, and thorough debriefing, which contemporary practice and ethics codes strictly govern.