1. A computer implemented method of classifying data associated with characteristics of persons within a population of persons, comprising: assigning a plurality of values to each of a plurality of terminal nodes associated with a previously generated classification tree, wherein each of the terminal nodes corresponds to a class of persons within the population of persons, and wherein each of the values associated with a particular terminal node is generated based on the frequency of occurrence of one of the classes at that terminal node and the frequency of occurrence of that one of the classes within the population of persons; reassigning at least one of the plurality of terminal nodes to a different one of the classes of persons based on a comparison of at least two of the assigned values to form a modified classification tree; classifying data records within the data based on the modified classification tree so that each data record within the data is associated with only one of the classes of persons; and displaying information associated with characteristics of persons based on the classified data records.