1. A method of developing a propensity model for an event using one or more computer implemented routines, wherein the routines when executed by a processor perform actions comprising: establishing a set of functions to represent a range of data inputs, each data input having a corresponding output, wherein each function represents a sub-range of the range of data inputs; processing the set of functions to establish new sub-ranges of the range of data inputs; and establishing a model for an event based on the new sub-ranges of data inputs and their corresponding outputs.