Two generalized rational models for forecasting innovation diffusion

This article demonstrates the development and use of two Generalized Rational Models I and II (GRM I and II) representing innovation diffusion. Specifically, the GRM II covers the same area as the NSRL model, which includes the Coleman and the Blackman/Fisher-Pry models, while the GRM I covers the same area as a modified NSRL model (mod. NSRL), also introduced hereby, and including Floyd, Blackman/Fisher-Pry, Sharif-Kabir and Exponential models. Both the GRM I and the GRM II provide a form of differential equation which always has for a solution a fact which cannot be met when dealing with the NSRL and mod. NSRL models.Some applications are presented, first to illustrate the wide applicability and the usefulness of the models and second to demonstrate the alternate use of the GRM I and mod. NSRL, and GRM II and NSRL models, which usually approximate very well.