Abstract
Rules can be induced from a decision table based on rough sets.When the decision attribute is ordinal,inducingdecision rules inferringmembers of upper and lower cumulative decision classes is moreadvantageous than inducing decision rules inferring members ofdecision classes. An inclusion relation holds forany two upper (lower) cumulative decision classes.Nevertheless, the rule induction forcumulative decision classes has been performedindependently, so far. As the result, there is no guaranteethat for a decision rule R there is a decision rule P whosepremise is weaker (resp. stronger) than R's premise even whenP's conclusion is weaker (resp. stronger) than R's.In this paper, we propose a rule induction methodto reduce the occurrence of such an inconsistency byincorporating the relations of cumulative decision classesin rule induction.
