This paper presents a theoretical framework for viewing elements that comprise distance education instructional systems in terms of dialogue. It is assumed that learning is mediated by intrapersonal dialogue and facilitated by interpersonal dialogue. Every resource in a distance education instructional system (eg, instructor availability, asynchronous communication networks, self-instruction texts, etc) is analysed in terms of the dialogue mode it supports. The framework offers three advantages: (1) a unified, simple, and coherent description of the mechanisms at play in distance education systems, (2) clear-cut operational definitions, and (3) hypotheses that may be investigated empirically.