Discriminant Function Analysis

The technique of discriminant function analysis was originated by R.A. Fisher and first applied by Barnard (1935). Two very useful summaries of the recent work in this technique can be found in Hodges (1950) and in Tosuoka and Tiedeman (1954). The techniques have been used primarily in the fields of anthropology, psychology, biology, medicine, and education, and have only begun to be applied to other fields in recent years. Classification and discriminant function analyses are two phases in the attempt to predict which of several populations an observation might be a member of, on the basis of multivariate measurements. Both procedures require that variables are measured on a series of observations of known population membership. Classification procedures match the profile of an observation on the original variables with the mean profile of the various predefined groups. Discriminant function procedures precede classification and produce a small number of linear functions of the original variables. These linear functions are derived so that they retain the maximum amount of information necessary to properly classify observations into groups