In this paper we present a novel approach to decomposing high dimensional s
paces using a multiobjective genetic algorithm for identifying (near-)optim
al subspaces for hierarchical classification. This strategy of pre-processi
ng the data and explicitly optimising the partitions for subsequent mapping
onto a hierarchical classifier is found to both reduce the learning comple
xity and the classification time with no degradation in overall classificat
ion error rate. Results of partitioning pattern spaces are presented and co
mpared with various algorithms.