Discriminant Analysis

Objective

Classify sample objects into two

or more groups on the basis of a

priori information

Discriminant Analysis

• Prediction of group membership is done

using one or more predictor variables and

one criterion variable.

• The criterion variable is categorical

Two variables of interest

• A multivariate analysis must first show a

significant difference between the groups

• The Wilks Lambda statistic

Example

• Distinguish between tropical and temperate

countries

Variables: calories, urban pop, pop, GDP

• D = a * calories + b * urban +

c * population + d * GDP

Assumptions

– The predictor variables follow a multivariate normal distribution

– Covariance matrices of different groups are homogeneous

Cluster Analysis

• Cluster Analysis is used to identify groups

• Given a large sample with multivariate data, identify a subset of the sample which is homogeneous

Distinguishing between groups

• Cluster Analysis

• Discriminant Analysis

• Neural Networks