This paper discusses and compares bidialectalism and various types of bilingualism, and the educational considerations presented by each. Stable bilingualism can result when each language is used by most, if not all, members of the community for different purposes. In a bilingual situation, societal factors are frequently such that no agreement can be reached as to the role each language should play. One language group may be materially wealthier and force members of the less-fortunate groups to abandon their language as well as their cultural values in order to share the wealth. Bidialectal individuals possess both a socially stigmatized and a prestige variety of the same language. Both bidialectalism and bilingualism as they are found in the United States are mainly of the transitional type. Both phenomena seem to be marked with some degree of strife or social tension. The resolution of the social imbalances accompanying both situations, however, will probably not be the same. (Author/VM)