This study presents an attempt to organize and validate a set of guidelines to assess the persuasive characteristics of interfaces (web, software, etc.). Persuasive aspects of interfaces are a fast growing topic of interest; numerous website and application designers have understood the importance of using interfaces to persuade and even to change users’ attitudes and behaviors. However, research has so far been limited by a lack of available tools to measure interface persuasion. This paper provides a criteria-based approach to identify and assess the persuasive power of interfaces. We selected164 publications in the field of persuasive technology, and we used those publications to define eight criteria: credibility, privacy, personalization, attractiveness, solicitation, priming, commitment, and ascendency. Thirty experts in human-computer interaction (HCI) were asked to use guidelines to identify and classify persuasive elements of 15 interfaces. The average percentage of correct identification was 78.8%, with Randolph’s kappa coefficient = 0.61. These results confirm that the criteria for interactive persuasion, in their current form, can be considered as valid, reliable, and usable. This paper provides some inherent limitations of this method and identifies potential refinements of some definitions. Finally, this paper demonstrates how a checklist can be used to inspect the persuasiveness of interfaces.