In analogy with Thomas Kuhn's definition of a scientific paradigm, Dosi has defined a technological paradigm as the general "outlook" on the productive problems faced by firms. As such, a technological paradigm is composed by some sort of "model" of the technology at stake (e.g. the model of a microprocessor) and by the specific technological problems posed by such model (e.g. increasing computational capacity, reducing dimensions, etc.). Therefore, technology is identified as a problem-solving activity in which the problems to be solved are selected by the paradigm itself. In this sense, a technological paradigm entails strong prescriptions on the "direction" of technological change, that is the direction toward which future technical improvements will converge. Such gradual improvements along the specific lines prescribed by the paradigm are what constitute technological trajectories and progress.