An attempt is made to provide a comprehensive guide to design of the dialogues between man and computer that take place at computer terminals. Particular topics include problems with conventional alphanumeric dialogues, dialogues with sound and graphics, pyschological characteristics of computer terminal users, problems of designing dialogues for naive or untrained operators, and considerations for design implementation. Appendixes provide an example of a psychiatrist-machine dialogue and exercises for the reader. (Author/RH)