A method for determining an estimate of a response characteristic that depends on a number of input factors includes developing a mathematical model of the response as a function of the input factors based on a statistical fit of a plurality of measured data points. The method also includes mapping the value of the response characteristic and the input factors at a plurality of conditions. The method combines the mapped data with the mathematical model to produce an estimate of the response characteristic that is more accurate over a range of conditions than either the mapped data or the model taken individually.