Audiences, who cannot investigate the credibility of most news stories for themselves, rely on noncontent heuristic cues to form credibility judgments. For most media, these heuristics were stable over time. Emerging formats of journalism, however, require audiences to learn to interpret what new heuristics credibility cues mean about the story’s credibility. In an experiment, participants (N = 254) were given instructions about how to interpret the credibility cues in three formats as they read a politicized news story, which were compared with a control condition with no instructions. Results show the timing and source increase the effectiveness of the instructions.