In the field of human-computer interaction studies, the need exists to understand how computers can be made more effective in cooperating with people. Difficulties are caused by lack of a general model for the flow of information, actions, and psychological aspects between humans and computers. This paper proposes an information-based model of human-computer interaction that takes into consideration the nature of the things that flow between them. The resultant model provides a basic framework for studying various notions in the area of human-computer interaction.