The measurement and/or storage of high order probability distributions implies exponential increases in equipment complexity. This paper considers the possibility of storing several of the lower order component distributions and using this partial information to form an approximation to the actual high order distribution. The approximation method is based on an information measure for the "closeness" of two distributions and on the criterion of maximum entropy. Approximations consisting of products of appropriate lower order distributions are proved to be optimum under suitably restricted conditions. Two such product approximations can be compared and the better one selected without any knowledge of the actual high order distribution other than that implied by the lower order distributions. © 1959.
Lewis, P. M. (1959). Approximating probability distributions to reduce storage requirements. Information and Control, 2(3), 214–225. https://doi.org/10.1016/S0019-9958(59)90207-4