The use of visual media in the classroom contributes to the improvement of teaching and learning. The purpose of this handbook is to present a practical discussion of the principles involved in designing visuals that teach. The author first describes the essentials of communication applied to instructional visuals. He then analyzes the physical characteristics of an instructional visual, noting the psychological consequences of these physical features. He outlines the elements of design--space, line, shape, size, texture, and color--and discusses the use of these elements to produce an effective, communicating visual. In conclusion, he discusses the application of the systems approach to decision-making in the design of visual aids. A bibliography of books, periodicals, and films is appended. (JY)