This article reviews Joan Robinson’s contribution to the issue of technical progress and her attempts, over the long term, to deal with this issue within the Keynesian theory of employment and income distribution. This paper examines this aspect of her work and suggests systematization and a formalization of her approach. The paper further highlights the problems she faced and did not always solve. Looking through her main contributions, the paper concludes that she used different criteria to classify innovations depending on the specific situations described by the models for which she used the classification.