We will continue here the research work, the goal of which was to intr
oduce the notion of nondeterministic aggregation operators and study t
heir properties, even in relation to classification systems and the as
sociated learning problem. Here we will concentrate mostly on the noti
on of the nondeterministic aggregation system and its relation with de
terministic ones. We will also see how such a model extends a discreti
zed version of a model of participatory learning with an arousal backg
round mechanism. (C) 1998 John Wiley & Sons, Inc.