Effective online review component design plays a critical role in facilitating online transactions. Although there is abundant evidence that consumer reviews have significant impact on product sales, the design of consumer review systems and its impact on consumers’ beliefs about online reviews and subsequent purchase decisions have not yet been thoroughly examined. Little theoretical knowledge is available about how review components may influence consumers’ beliefs, attitudes and behavior. In this paper, we develop a conceptual model for measuring the impact of review components on the beliefs and behavior of online customers. In developing the theoretical model (called the influence of review components model, or IRCM), we synthesize the theory of reasoned action with theories in social psychology, consumer behavior, and trust to categorize review components and conceptualize the salient beliefs of consumers toward online reviews. We expect that IRCM and its empirical results provide an initial guideline for a rigorous approach to designing online review systems and testing their effectiveness before full deployment