Fogg, B. Persuasive computers: perspectives and research directions. In CHI ’98: Proceedings of the SIGCHI conference on Human factors in computing systems (New York, NY, USA, 1998), ACM Press/Addison-Wesley Publishing Co., pp. 225–232. [PDF]
This paper contain a seminal definition of the domain of persuasive technologies, named captology. The author defines five different perspective on computers and persuasion. His original definition of persuasion is: an attempt to shape, reinforce, or change behaviors, feelings, or thoughts about an issue, object or action. According to the author, the persuasive nature of technology does not reside with the object itself. Instead, the persuasive nature of technology depends on the context of creation, distribution, and adoption. In particular contexts, technology inherits a type of intent from human actors. Finally, the paper lists seven research directions for captology.