It is well-known that ethnic affiliation and mother tongue claims are variable, involving both primordial ties and deliberate choices. These choices are constrained by political language regimes. The promotion of a common standard through schooling, print media, etc. is a significant factor in this regard. If classification poses problems in Europe where language divisions have been made explicit a long time ago, where the number of unwritten languages is small, and where scientific dealings with classifications have a long tradition, the problems can be expected to multiply in the area covered by the present survey which is characterized by a much higher density of unwritten languages and aggregates of speech varieties whose mutual relationships are not altogether clear. Such cases are especially numerous in East and Southeast Asia, but in China, too, language recognition is still a topic on the agenda of sociolinguistic research.
Language names are no solution to the classification problem either.
Antonymes differ from names used by outsiders. Languages may be known by several different names. Language names do not always coincide with those of ethnic groups, and ethnic groups may cut across speech communities such that a single speech community is made up of several different ethnic groups or a single ethnic group is composed of a number of speech communities. These are just some of the difficulties involved in language classification. Pertaining as they do to our understanding of what a language is, they touch upon a raw nerve of the science of language.