Abstract
This paper develops Lewis’ notion of convention within a framework that mixes cognitive science with some more social theories of activity like distributed cognition and activity theory. The close examination of everyday situations of convention-based activity will produce some interesting issues for a cognitive theory of behavior. Uncertainty, dynamics, and the complexities of the performance of convention-based activities that are distributed over time and/or place, are driving factors in the analysis that is presented. How the actors reason and manage their collaboration is characterized as pragmatic action. During the course of recurrent activities, the participants adapt previously learned convention-based activities to new circumstances. The coordinating representations that are a part of the design of the context mediate parts of the activity. As they act, the participants learn.