大多數的企業普遍希望透過共同品牌的策略來獲取更高的獲利。然而，共同品牌的策略是否總是能為企業帶來正面的效果呢？尤其是這樣的策略對消費者來說是不是也能產生正面的評價呢？
本研究便以過去對情境效果的相關研究為理論基礎(構面範圍重疊模式及包含/排除模式)去解釋消費者對共同品牌的評價，檢視一個品牌如何去影響另一個品牌及消費者對共同牌的評價為何。從本研究的三個實驗結果發現，同化效果、異化效果的發生取決於目標品牌及情境品牌間的解釋範圍是否有重疊。跟過去探討共同品牌的研究結果不同的地方在於，當目標品牌跟一個好的品牌合成一個共同品牌的時，不一定都是會產生同化效果，也有異化效果的可能性發生。這樣的研究結果，可以提供給所有的行銷人員當作參考，並不是使用共同品牌策略：把一個好的品牌跟另一個品牌合在一起後，總能為另一個品牌帶來正面的效果，應當考慮兩個品牌原來的解釋範圍有沒有重疊。如果兩品牌原來的解釋範圍有重疊時，則使用共同策略，確實能產生同化效果；反之，共同品牌策略則有可能產生異化效果。

A lot of businesses are enthusiastic at embracing the co-branding strategy in order to acquire more profit. However, would co-branding strategy always engender positive outcome? In particular, would consumers’ attitude be necessarily manipulated in a favorable way when encountering the persuasive communication consisting of positive co-branding?
The present research is concentrated on the examination of how a context brand may influence a target brand through the mechanism proposed by the theories critical to context effect, such as Dimensional Range Overlap Model and Inclusion-Exclusion Model. The experimental designs were applied in three studies conducted to investigate the potential effect of co-branding on the product assessment. As a result, the finding of the studies demonstrated that, contrary to what co-branding relevant literature noted, assimilation and contrast could occur in response to the overlap or non-overlap between the interpretation range of target brand and context brand.
The traditional wisdom and past literature suggested that as long as the target brand is co-exposed with a favorable context brand, the target brand would be evaluated better than when no favorable context brand is co-exposed. However, the finding of the current research indicated that contrast effect was likely to occur as well such that the target brand might be evaluated worse rather than better even when a favorable context brand was served as a co-brand.

Bless, H., & Schwarz, N. (1998). Context effects in political judgment:. Assimilation and contrast as a function of categorization processes .European Journal of Social Psychology, 28, 159-172.
Hsiao, C. C., & Y. W. Chein , 2004. On the Biasing Judgment of Innovation:
Context effect of Existent Brand. Taiwan Academy of Management Journal, 4(1) , 313-332.
Herr, Paul M., Steven J. Sherman, and Russell H. Fazio (1983), “On the Consequences of Priming: Assimilation and contrast Effects, “ Journal of Experimental Social Psychology, 19(July), 323-40.
Higgins, E.T.(1996). Knowledge activation: Accessibility, applicability, and salience. In E.T. Higgins & A. W. Kruglanski(Eds.), Social psychology: Handbook of basic principles(pp. 133-168). New Youk: Guilford.
Judith, H. W., Brian, D. T,. & Randi, P, 2004. Brand alliance and customer-based brand-equity effects. Journal of psychology & marketing , Vol.21(7):487-508.
Levin, A.M. (2002), “Contrast and assimilation processes in consumers’ evaluations of dual brands.” Journal of Business and Psychology, vol. 17, no. 1, 145-154.
Levin, A. M, 1997. Context effects in brand judgment: An investigation into consumers' reactions to dual branding. Unpublished doctoral dissertation, University of Kentucky.
Levin, A. M., Davis, J. C., & Levin, I. P. (1996). Theoretical and empirical linkages between consumers’ responses to different branding strategies. In K. Corfman & J. Lynch(Eds.), Advances in consumer research(Vol.23, pp. 296-300). Provo, UT: Association for Consumer Research.
Levin, I. P. & Levin, A. M. (2000). Modeling the role of brand alliances in the
assimilation of product evaluations. Journal of consumer psychology, 9 (I), 43-
52.
Marina Pronskaia , 1999 . Alternative brand naming strategies for bottled water division of group danone in British Columbia . BBA, International business, Schiller International University.
Martin, John J. Seta, and Rick A. Crelia(1990), “ Assimilation and Contrast as a Function of People’s Willingness and Ability to Expend Effort in Forming an Impression, Journal of Personality and Social Psychology, 59(July), 27-37.
Martin, L. L., & Tesser, A. (1992). The construction of social judgments. Hillsdale, NJ: Lawrence Erlbaum Associates, Inc.
Meyers-Levy and Sternthal, 1993. A two-factor explanation of assimilation and contrast effects. Journal of Marketing Research,30, 359-368.
Rao, A. A. & Ruekert, R. W. (1999). Signaling unobservable product quality through abrand ally. Journal of Marketing Research, 36 (May), 128-168
Rao, A.R. & Ruekert, R. W. (1994). Brand alliances as signals of product quality. Sloan Management Review, 36 (Fall), 87-97.
Schwarz, N., & Bless, H, 1992. Construction reality and its alternatives: An inclusion/exclusion model of assimilation and contrast effects in social judgment. In L. Martin & A. Tesser (Eds.),The construction of social judgment(p.217-245).Hillsdale, NJ; Lawrence Erlbaum Associates, Inc.
Sedikides, C., & Skowronski, J.J.(1991). The law of cognitive structure activation. Psychological Inquiry, 2, 169-184.
Sherman, S.J., R. Ahlm, L. Berman and S. Lynn (1978), "Contrast Effects and Their Relationship to Subsequent Behavior." Journal of Experimental and Social Psychology, 14, 340-350.
Stapel, D. A., & Spears, R. (1996). Event accessibility and context effects in causal inference: Judgment of a different order. Personality and Social Psychology Bulletin, 22, 979-992.
Stapel, D.A.(1997). What we talk about when we talk about knowledge accessibility effects. Unpublished doctoral dissertation, University of Amsterdam , Amsterdam.
Wyer,R.S., Srull, T.K.(1989) Memory and social cognition in its social context. Hillsdale, NJ; Lawrence Erlbaum Associates, Inc.