本文探討多數/少數效果對產品態度的影響，是否會受到渉入程度以及訊息相關性的干擾。我們認為在不同渉入程度之下，多數/少數訊息來源對產品態度的影響能扮演不同角色。在低渉入之下，多數/少數訊息來源被視為一種週邊線索，可以直接影響產品態度；在中渉入之下，多數/少數訊息來源會影響消費者處理產品訊息的程度；在高渉入之下，當多數/少數訊息來源與判斷產品的品質相關時，就會被視為是核心論點之一，並會偏誤對所有核心論點的處理。本文為首先提出整合架構，解釋多數/少數效果在低中高三種渉入程度下以不同機制影響產品判斷的研究。

This study investigates the majority/minority effects on product attitudes with involvement and source relevance as moderators. We posit that the majority/minority source can play different roles affecting product judgments at different involvement levels. It can serve as a peripheral cue directly influencing product attitudes under low involvement; it can alter the processing amount under moderate involvement; finally, it can serve as a central argument and bias processing if it is perceived as relevant to judging the true quality of the target product under high involvement. The current study is the first to provide an integrated framework to explain the different mechanisms by which the majority/minority may influence product judgments under three involvement levels (low, moderate, and high).