Argumentation constitutes 1 of the most common forms of human interaction. Yet despite its pervasiveness, relatively little psychological research has been conducted on the topic. This article serves as an introduction to this research and has 2 goals. One is to discuss a number of general issues relevant to the study of argumentation, including the definition, goals and functions, structure, evaluation of arguments and argumentation, and the relation of narrativity and argumentation. The 2nd goal is to describe some examples of the existing psychological research on argumentation, with emphasis on articles in this special issue. Topics include argumentation by children, argumentation skill, writing argumentative text, argumentation and case-based change, argumentation and critical thinking, and argumentation and narrativity in a legal context.