JOURNAL OF REGIONAL SCIENCE, VOL. 13, NO. 2. 1973 5). We then noticed that when the curves constructed for testing the model were ally shifted to the right, the fit of the model to the data seemed to be fairly Such a shift would also yield a more realistic view of the diffusion process, the rate of adoption starts at zero, increases to an inflection point, and then decreases until some saturation level is reached, resulting in the well-known logistic growth curve. Because we had considered it possible to conceptualize the diffusion process in terms of energy inputs into the system, we wondered if it would be possible to Distance(or Time) FIGURE 1: Changing Form of a Single Wave with Time and Distance Interchangeable T Distance FIGURE 2: anging Form of an Innovation Wave, Acceptance Over Distance at Given Time Periods FIGURE 3: Changing Form of an Innovation Wave, Acceptance Over e at Given Distances