Previous research has drawn upon warranting theory to help explain how viewers evaluate people and entities online. Extending previous research, this study assesses how the ability of a target to modify third-party information affects perceptions of warranting value, and in turn, interpersonal impressions and the perceived legitimacy of online media that host evaluations. Additionally, this work explores how the perceived objectivity of a third-party evaluator affects impressions in online settings. The results provide support for warranting theory and help clarify how impressions are formed in online environments when people have the ability to generate and modify content collectively. The theoretical implications this study has for warranting theory and future research directions are discussed.Whether it is an employer evaluating a job candidate or a single person yearning to meet a compatible partner, people assess information in an attempt to form impressions of others. Understanding why information is and is not impactful in the impression formation process has received considerable research attention. Given the apparent mistrust individuals have about the veracity of claims made through newer media (see Walther & Parks, 2002), the emergence of scholarly attention to these processes is understandable. The primary aim of this study is to examine how people evaluate information appearing online when the potential exists for it to be collectively generated and modified by multiple individuals. Using collaborative online media for interpersonal evaluationsMany popular websites, including Facebook, eBay, YouTube, and Wikipedia, invite users to contribute material and to respond to others' contributions. Additional Evaluating collaboratively created informationNew media provide users many opportunities to contribute information online for subsequent viewers to see. Through some communication platforms, people are Journal of Communication 65 (2015) 62-78