1. A method for estimating a rank order for records with respect to a selected characteristic of subjects of said records, said records including attributes of said subjects, and said attributes including a categorical attribute said method comprising the steps of: a) estimating a statistic relating values of said categorical attribute to said characteristic; b) for one of said records, applying a feature vector having elements derived from said attributes in said one record, said elements including a value of said statistic corresponding to a value of said categorical attribute in said one record, to an artificial intelligence algorithm to obtain an output value; c) repeating step b for each remaining one of said records; and d) rank ordering said records in accordance with said output values.