This chapter explains how credibility is established and communicated in digital spaces, both subjectively and objectively, and how these activities differ from those for traditional media. At the heart of these differences is the fact that interactors do not merely read or view; as the term implies, they interact with the content, because digital media, in sharp contrast with print and broadcast media, rely on spatial relationships. Most digital spaces, and certainly the good ones, facilitate and encourage interaction and movement. All three of the important roles of the writer (communicator, organizer, and interpreter) rely upon the writer's and the digital space's credibility. The ways in which credibility is established, maintained, and measured in digital spaces are different than those for traditional media. Credibility studies suggest several elements that can give interactors confidence and engender trust in a digital source and its authors. Briefly, these include: easy-to-use, intuitive navigation and user-friendly design.