The Thesis aims to improve, on theoretical and pratical terms, the modeling of economic valuation of investments under high uncertainty, such as Research and Development projects (R&D), especially those that are incremental in nature. From a valuation model based on the design of Real Options Theory, it incorporates a more complete view of uncertainty, which reaches the decisionmaking aspects of the act, known as knightian Uncertainty, where the concepts of risk and uncertainty are separated. The full implementation of the concept of Knight (1921) on quantitative models is possible according to the mathematical development of Schmeidler (1982), which resulted in a new formula for calculation of expected values, based on the Choquet integral (1953). The new model includes a calculation of expected value that makes it possible for the agent to recognize an uncertainty aversion in this concept, known as the Choquet expected value.