HIERARCHIES OF AGGREGATION OPERATORS

This article deals with hierarchies of operators. In particular, we wi ll analyze the problem of amalgamating individual opinions into a sing le group opinion, based upon hierarchical intensity aggregation rules. Our main goal is to decide whether hierarchical amalgamations are sup ported from an ethical and rational point of view. We will consider tw o different hierarchical procedures: cover-based hierarchical aggregat ions and ordered hierarchical aggregations, focusing here our attentio n to ordered hierarchical aggregations of OWA operators. In particular , we will obtain that basic key properties propagate under both hierar chical amalgamation rules, in the sense that the procedure itself will verify such properties whenever they are assumed for every partial am algamation defining such a hierarchical procedure. (C) 1994 John Wiley & Sons, Inc.