IBM Support

Quadratic discriminant analysis in SPSS



The results of Box's M test from a discriminant analysis indicate that the assumption of the equality of covariance matrices is not supported. I understand that quadratic discriminant analysis does not require this assumption. Can I perform a quadratic discriminant analysis in SPSS?

Resolving The Problem

Quadratic discriminant analysis is not available using SPSS. However, you can choose to classify cases based upon separate covariance matrices (as opposed to the default use of the pooled covariance matrix). Using separate covariance matrices is one way to get around the problem of inequality of covariance matrices. When the number of predictors does not exceed the number of groups minus 1, the results of classifying cases using separate covariance matrices are identical to the results from quadratic discriminant analysis.

[{"Product":{"code":"SSLVMB","label":"IBM SPSS Statistics"},"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Component":"Not Applicable","Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"Not Applicable","Edition":"","Line of Business":{"code":"LOB10","label":"Data and AI"}}]

Historical Number


Document Information

Modified date:
16 April 2020