Graduation date: 2007The EBM model of consumer decision making was used to guide the present study. According to this model when consumers make purchase decisions, they search for information from either internal and/or external sources. When consumers do not have enough information from internal sources, such as knowledge and experiences, they search information from external sources, including market-dominated, consumer-dominated, and neutral sources. As the population of Internet users grows, consumer-dominated communication on the Web, also called Internet WOM, is also increasing. Consumer reviews, one of the ways consumers exchange opinions and experiences on products and services on the Web, have been successfully practiced. Nonetheless, research on the effectiveness of consumer reviews has not yet been done. Thus, this study aimed to investigate the effectiveness of consumer reviews, specifically the source credibility of consumer reviews according to different types of review features, such as content of reviews, presence of a reviewer’s photo, and type of a reviewer’s name. In addition, the relationship between the perceived credibility of a reviewer and the perceived risk associated with online purchase was also examined. Using an online survey method, two hundred and ninety-two female students voluntarily participated in this study and received extra credit points for their participation. A 2×2×3 complete factorial experiment was used to examine source credibility— attractiveness, expertise, and trustworthiness—of consumer reviews of apparel. The three independent variables were the content of reviews with two treatments (a general review and a specific review), the presence of photo with two treatments (absence of a reviewer’s photo and presence of a reviewer’s photo), and the type of a reviewer’s name with three treatments (anonymous, an identifiable with an ID, and an identifiable with a real name reviewer). The results revealed that 1) specific reviews increased source attractiveness, expertise, and trustworthiness, 2) a review without a photo of a reviewer increased source attractiveness and had no effect on the others, and 3) type of a reviewer’s name had no effects on source attractiveness, expertise and trustworthiness. An additional finding was that the higher the perceived source credibility the greater the reduction in the perceived risk associated with online shopping. The results of this study have implications for consumer researchers to further investigate the effectiveness of consumer reviews. Additionally, the findings can inform apparel e-retailers in determining whether to include consumer reviews as a feature and, if so, what criteria to include for consumer reviews.