discriminant analysis objective classify sample objects into two or more groups on the basis of a...
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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