Extending Athena: multiple classes and confidence output values

The Athena model, introduced by C. Koutsougeras and C.A. Papachristou (1988), is a tree-like net whose adaptation is based on entropy optimization. The difficult problem in the optimization was handled by using Fisher´s linear discriminant method. To handle the multiple class case, heuristics were used (multiple classes, generic classes) to reduce the problem at hand to the two-class case. In the present work, it is shown that the more general Fisher method of multiple discriminants is very effective in directly handling the multiple classes case. A method is also presented by which confidence values are produced for the overall classification decision