“…cit., 1980, p. 20). For example, both the authoritative article by W. E. Lambert [13] in International Dimensions of Bilingual Education, and the overview of recent research by Merrill Swain and James Cummins (1979) [14], draw attention to the positive advantages of bilingualism, but show how 'bilingual education' covers a whole range of programmes with very different emphases and objectives, in terms of skills to be mastered. Contradictory results from studies of education through more than one language medium will continue to abound, not only because of methodological difficulties of comparing different research projects, but also because of the problem of matching the many variables that can influence particular sociolinguistic contexts.…”