As a first step in a systematic approach to instructional design, an attempt is made to develop public linguistic systems which would permit a designer to communicate with his colleagues. Abstracting general principles of design from fields other than education, an organized body of instructional design concepts emerges. These concepts are then used to decompose the contexual requirements normally found in a CAI program. The instructional elements found in an analysis of a series of recursive questions cluster into six major factors: control, organization, outcomes, reinforcement, display, and response. Three languages (a natural language, an artificial language, and a computer language as a synthesis of the two) are proposed to string together these conceptual elements to form syntactical structures. In general, the computer version is found to be most powerful. Finally, 50 randomly selected CAI programs are analyzed in order to find recurring instructional patterns. Five operationally defined patterns occur repeatedly within or between programs. A suggestion is made that these reusable patterns could constitute the new lexical elements of a metalanguage to generate patterned structure of instructional programs in the future. (CH)