ABSTRACT
A large body of the literature on innovation consists of attempts to analyse changes that have already taken place and from these analyses, models are abstracted in order to help future planned change. R. G. Havelock's major conclusion is that the principal models of dissemination and utilisation of knowledge used by most people can be grouped under three perspectives: research, development and diffusion; social interaction; and problem-solving. D. A. Schon notes two important variants of the centre–periphery model: the 'Johnny Appleseed' and 'magnet' models. Sources of failure are variants of the conditions that bring about failure in the simpler centre–periphery model. E. M. Rogers and F. F. Shoemaker identify five characteristics: relative advantage, compatibility, complexity, trialability and observability. The idea underlying the identification of characteristics of innovations by various writers is to relate the characteristics to the rate of adoption of innovations. The characteristics of trialability and observability are more problematic in the field of education.
