Although this thesis is focusing on combining neural networks, for completeness of this
section we feel it is necessary to mention that a few experiments have been done with
hybrid ensembles. Wang et al [146] combined decision trees with neural networks. They
found that when the neural networks outnumbered the decision trees, but there was at least
1 decision tree, the system performed better than any other ratio. Langdon [82] combines
decision trees with neural networks in an ensemble, and uses Genetic Programming to
evolve a suitable combination rule. Woods et al [150] combines neural networks, k-nearest
neighbour classifiers, decision trees, and Quadratic Bayes classifiers in a single ensemble,
then uses estimates of local accuracy in the feature space to choose one classifier to respond
to a new input pattern.