ABSTRACT
For a long period, stuttering research has focused on developing and refining various ways of measuring speech, as well as on the physiologic, affective, and cognitive responses of people who stutter. These measurement methods have been applied primarily in research comparing people who stutter with those do not stutter. Frequent ambiguities and inconsistencies in the resultant data have been blamed, variously, on insensitive measures, imprecise technology, observer variability, or even bias. Relatively less thought and effort have been invested in investigating the possibility that the cause of much of the ambiguous contradictory data lies not with the observers or measures employed, but with the heterogeneity of those being observed. All too often, basic facts about differences within the population of people who stutter or their families have been ignored in the current body of research, sometimes in very significant ways. Several attempts to subtype stuttering through developmentally oriented classification schemes or using other bases, such as symptomatology (see review by Yairi, 1990), have not been submitted to thorough research or have failed to receive sufficient scientific support. This being the case, it is not surprising that subtyping or subgrouping systems have enjoyed little recognition in either the research or clinical domains. In spite of a notable recent attempt to identify subgroups (Schwartz & Conture, 1988), by-and-large, stuttering has continued to be dealt with in our laboratories, and treated in our clinics as a unitary disorder, a “pathognomonic monolith,” as it was labeled by St. Onge (1963).
