The flow diagram is based on the concept of a systematic flow of the material to be learned and its gradual ‘thinning-out’ in a manner similar to that of an exponential decay function. The ‘thinning out’ varies inversely with the complexity of the concept involved and the diagram facilitates the introduction and manipulation of a unit of knowledge or subject matter stimulus. Thus the flow diagram is drawn to serve the following functions:

(a) to record the overall sequence which will govern the writing of frames;

(b) to provide a record of the estimated number of frames needed to learn each concept and rule;

(c) to record the types of frame required in the programme and to record the fading or vanishing of prompts or cues;

(d) to record the location of revisionary and consolidation sequences;

(e) to indicate the type of presentation and the frame coding requirement.