varieties of Ojibwe form a dialect continuum, a series of adjacent dialects spoken primarily in the area surrounding the Great Lakes as well as in the Canadian provinces of Quebec, Manitoba, and Saskatchewan, with smaller outlying groups in North Dakota, Montana, Alberta, and British Columbia. Mutual intelligibility is the linguistic criterion used to distinguish languages from dialects. In straightforward cases, varieties of language that are mutually intelligible are classified as dialects, while varieties of speech that are not mutually intelligible are classified as separate languages. Linguistic and social factors may result in inconsistencies in how the terms language and dialect are used. Languages spoken in a series of dialects occupying adjacent territory form a dialect continuum or language complex, with some of the dialects being mutually intelligible while others are not. Adjacent dialects typically have relatively high degrees of mutual intelligibility, but the degree of mutual intelligibility between nonadjacent dialects varies considerably. In some cases, speakers of nonadjacent dialects may not understand each other's speech. A survey conducted during the 1980s and 1990s found that the differences between Ottawa, the Severn Ojibwe dialect spoken in northwestern Ontario and northern Manitoba, and the Algonquin dialect spoken in western Quebec result in low levels of mutual intelligibility. These three dialects "show many distinct features, which suggest periods of relative isolation from other varieties of Ojibwe." Because the dialects of Ojibwe are at least partly mutually intelligible, Ojibwe is conventionally considered to be a single language with a series of adjacent dialects. Taking account of the low mutual intelligibility of the most strongly differentiated dialects, an alternative view is that Ojibwe "could be said to consist of several languages", forming a language complex. Geographic distribution The Ottawa communities for which the most detailed linguistic information has been collected are in Ontario. Extensive research has been conducted with speakers from Walpole Island in southwestern Ontario near Detroit, and Wikwemikong on Manitoulin Island in Lake Huron. South of Manitoulin Island on the Bruce Peninsula are Cape Croker and Saugeen, for which less information is available. The dialect affiliation of several communities east of Lake Huron remains uncertain. Although "the dialect spoken along the eastern shore of Georgian Bay" has been described as Eastern Ojibwe, studies do not clearly delimit the boundary between Ottawa and Eastern Ojibwe. Other Canadian communities in the Ottawa-speaking area extend from Sault Ste Marie, Ontario along the north shore of Lake