Symbolic Interpretation of Artificial Neural Networks

Hybrid Intelligent Systems that combine knowledge based and artificial neural network systems typically have four phases involving domain knowledge representation, mapping of this knowledge into an initial connectionist architecture, network training, and rule extraction respectively. The final phase is important because it can provide a trained connectionist architecture with explanation power and validate its output decisions. Moreover, it can be used to refine and maintain the initial knowledge acquired from domain experts. In this paper, we introduce three new rule extraction techniques. The first technique extracts a set of binary rules from any neural network regardless of its kind (MLP, RBF etc.,). The second technique extracts partial rules that represent the most important embedded knowledge in a trained network. The fidelity of the second technique is adjustable to the desired level of knowledge extraction. The third technique is a comprehensive and universal approach. A ru..