ABSTRACT
This chapter deals with an extremely significant problem that humans as planners and social agents often confront. A number of studies have addressed the potential validity of the hierarchy principle. Among these studies are several that were designed to test the principle directly, whereas another study to be considered provides an indirect test of the principle. In some of the studies, differential responses to these failures were taken as evidence for alterations of message-plan hierarchies at various levels. The two renditions of the directions were compared to determine the hierarchical levels at which message plan alterations were made. The most demanding alteration to the message plans underlying the directions would be to reformulate them completely by providing a new route in the second rendition. The pedestrians were approached at the same intersection and asked for directions to the university stadium. After providing the first rendition of the directions, the experimenter gave one of the two locus of communication failure inductions.
