Two experiments used clinical validation to increase scrutiny of messages posted in public settings. The first experiment used a 2 (validation: no/yes) × 2 (persuasion: none/"it is important") factorial design to develop messages about newspaper recycling. The prompt (no validation/no persuasion) had little impact on newspaper recycling, but the other 3 signs all resulted in increased recycling while the signs were in place. After signs were removed, recycling remained significantly higher than baseline (marginally significant for validation/persuasion). At the end of the study, number of cognitions favoring recycling was significantly higher in the validation-only condition and was lower in the validation/persuasion condition. Experiment 2 tested whether signs would have more impact if they were sensitive to the social ecology of newspaper recycling; that is, readers' tendency to leave newspapers behind so others may read them. Messages based on a 2 (message: validation-only/validation plus persuasion) × 2 (ecology: no social ecology/social ecology) factorial design supported social ecology's importance. Furthermore, because of the increased sharing in the social ecology conditions, total numbers of newspapers used was significantly lower in those buildings. Validation only yielded sustained behavior change in both Experiments 1 and 2, supporting additional research on the question of whether validation can, by itself, lead to cognitive elaboration and self-persuasion.