IWG Credibility was a joint interdisciplinary group aimed at defining trust and credibility in social media. The following abstract is from the outcome of this effort. In our review, we gathered current definitions, models, and measurements from the fields of computer science, communication, information systems, and psychology. In summary, we argued in favor of using the term credibility when referring to the perceived characteristics of objects or entities (e.g., an information source or a message). We also found that the concept of trust encompasses the relationship between the information receiver and source and should, therefore, be used when such a connection exists. Moreover, we provided a comprehensive overview of the existing models and measurements from an interdisciplinary viewpoint.