The conflict resolution strategy of YAILS is a little naive. In effect whenever several rules "fire" during the classification of one example, and different conclusions exist, YAILS chooses the conclusion of the rule with highest opinion value (OV). This value is a measure of the confidence on the rule's opinion and it is calculated as follows :
This method is naive because if it happens the case where 10 rules fire, 9 saying X and 1 saying Y, and if the rule that says Y has higher OV then YAILS says Y, even if the other 9 rules have very similar OV's. Some traces of classification tasks were made and it was verified that this situation is not so common and perhaps that is the reason for the good results obtained with YAILS in spite of this method. Nevertheless this is a feature to improve in future versions of YAILS.