Richard Nolan's stage model is the best known and most widely cited model of computing evolution in organizations. The model's development over a decade demonstrates its own evolution from a simple theory, based on the factoring of change states indicated by changes in computing budgets, to an elaborate account of the characteristics of six stages of computing growth. An analysis of the model's logical and empirical structure reveals a number of problems in its formulation that help to account for the fact that its principal tenets have not been independently validated. The model is shown to be an "evolutionistic" theory within the theories of evolution in the social sciences, focusing on assumed directions of growth and an implied end state toward which growth proceeds, and suffering from problems inherent in such theories. Further research based on an "evolutionary" view of computing growth is suggested as a means of improving theories of computing in organizations. empirically grounded theory [27] and an accepted de- scription of how changes in organizational information systems take place over time [1, 2, 7, 13, 22, 29]. Despite the widespread attention Nolan's model has attracted, it has never been subjected to a careful ana- lytical review in the published literature. Given the importance of the model in the information systems field, and the interpretations of data and prescriptions for management based upon it, such a review is over- due. This paper reviews the basic structure of the model itself, discusses its use as a theory of evolution within the context of explanations of evolution describ- ing the social sciences, and assesses the model's practi- cal utility as a descriptor of the process of change in organizational information systems over time.