Computation of composite scoring system

Use of composite indices spans over an expansive research continuum from social to medical, basic to advanced and exploratory to confirmatory research. Constructs like severity of illness, quality of life, mental well being and customer satisfaction are usually measured by composite indices. Weighing scheme used to develop a composite score can vary. Equal weighting simply means that each item of data used is scored similarly and has same importance in the final score. In addition, a weighted composite score from various significant predictors can be developed using an appropriate weighting scheme. The first of these is principle components analysis (PCA), which assigns factor loadings for each item in the scale components. A second method of deriving weights for use in index aggregation is through regression processes.