This guide is designed to provide a basis for the effective design of instructional materials for distance education. Organized around a model of instructional development which encompasses both external structural factors (factors that are largely outside the direct control of the individual instructor but which must be investigated) and internal structural factors (factors that are internal to the materials themselves and are essential to their instructional effectiveness), the guide consists of three main sections. The three chapters of the first section present an overview of the model itself, provide a definition of each of the external and internal factors, and suggest a number of questions to guide the instructional developer in addressing each factor. The second section contains a separate chapter for each of the external structural factors: budget, course function, modes of communication, subject/unit characteristics, subject/unit location, lecturer characteristics, student characteristics, and professional assistance. A separate chapter is provided in the third section for each of the internal structural factors: arousal and motivation, goal definition, cognitive structuring, signposting, activation, feedback, transfer and retention, and assessment and evaluation. (GL)