If information science is to be considered a "science" in the true sense of the word, a set of general concepts and analytical expressions must be developed. Fundamental to this development is a rigorous and quantifiable measure of information. In previous papers a general framework, called a generalized information system, is suggested which permits the development of these concepts and expressions. Through the use of this generalized model, we have been able to define information quantitatively and in a rigorous manner. The formulation depends on the definition that "information is data of value in decision making" and leads to quantitative relationships between information and the value of a decision state. The value of the decision state is defined as the summation of the expected values of all the possible courses of action weighted by the probability of each course of action. A new measure for the information contained in a particular decision state is developed. The information is defined in terms of a two-choice deterministic situation which we call a "binary choice unit." This measure is universally applicable for all information that is concerned with the effectiveness of the data on the recipient. (Author)