If information science is to be considered a “science” in the true sense of the word, there is a clear need for the development of a set of general concepts and analytical expressions regarding the flow of information in any situation for which information serves as a resource. This paper discusses quantitative aspects of a theory leading to the development of such a pragmatic information theory. At the heart of a theory of pragmatic information is the measure of information contained in a set of data. At the pragmatic level, information has value to the extent that it is useful as a resource for purposeful activity. The primary “purposeful activity” in life is decision-making. Hence, information and decision-making are inextricably tied together; in fact, information is data of value in decision-making. In this paper, we discuss quantitatively a very general decision model which provides a formal and comprehensive representation of uncertainty in decision-making. Other decision models presented in the literature assume away a considerable and important portion of the uncertainty that exists in decision-making. This model is then used as a framework for examining the role of information in decision-making in a way that is also formal and comprehensive. Hence, the decision model suggested facilitates a meaningful analysis of information; this analysis culminates in the development of a measure of the value of the pragmatic information contained in a set of data.