The ability viewers have to contribute information to websites (i.e., user-generated content) is a defining feature of the participatory web. Building on warranting theory, this study examined how viewers' evaluations of a target are more or less likely to be influenced by user-generated content. The results indicate that the more a target is perceived to be able to control the dissemination of user-generated reviews online, the less credence people place in those reviews when forming impressions of the target. In addition, the less people are confident that user-generated reviews are truly produced by third-party reviewers, the less people trust those reviews. The results provide novel support for warranting theory by illustrating how the warranting value of user-generated information can vary and thus differentially affect viewers' evaluations of a target. The implications of the study's results for warranting theory, online impression management, e-commerce, and future research are discussed.

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Often, virtual environments and video games have established goals, and to achieve them, users must either compete or cooperate with others. The common ingroup identity model predicts that individuals maintain multiple identities at any given time based on roles, demographics, and contextual factors, and that they interpret others based on similarity (i.e., perceived ingroup) or dissimilarity (i.e., perceived outgroup) to these identities. In this experiment, we manipulated two aspects of a virtual partner's identity-race and task collaboration-to determine how users would perceive others in a virtual world. White participants (N=99) played an anagram game competitively (outgroup) or cooperatively (ingroup) in a virtual environment with a black (outgroup) or white (ingroup) virtual partner. Contrary to hypotheses, performing either task led to more positive evaluations of black avatars than white avatars.

This study extends the research on message-sensation value (MSV) by treating it as a dynamic stream of complex visual-auditory information and arousing content (MSV-d).Real-time attentional and emotional responses to this dynamic stream during the PSA viewing process are indicated by psychophysiological measures. Dynamic models are used to systematically examine endogenous and exogenous influences on message processing to more accurately understand the effects of MSV-d variables and individuals' sensation seeking tendencies during the processing of the PSAs. An important finding is that generally, increasing visual-auditory complexity activates an approach tendency in those with high sensation-seeking tendencies but activates an avoidance tendency in those with low sensation-seeking tendencies, and this response pattern is moderated by arousing content.

Consumers using online auction websites face the challenge of appraising products at a distance. Sellers and buyers in online auctions navigate this challenge by displaying and evaluating various cues, a critical one being use of photographs. Warranting theory predicts that cues less subject to control and manipulation by the presenter will be more influential in impression formation. Therefore, user-generated photographs which display the actual item should be more effective in generating successful auctions, more bidders, more bids, and higher prices, compared with stock photographs. A field experiment tested this prediction by systematically manipulating photographs for eBay auctions. User-generated photographs were found to have a positive effect on likelihood of selling and the number of auction bidders. Findings indicate that attracting more bidders is a possible mechanism for higher sale prices and also show a moderating role of bidder experience.