Thus, all the Turk peoples with the language belonging to the Kipchak branch of the Turk group are often considered as the offspring of Kipchaks. This approach ignores the fact that the names of the major part of language groups, including the Kipchak group, are merely conventional, and one should not conclude about the ethnogenetic commonality among the languages belonging to the same group. The sources for ethnogenetic study As noted, the basic source of information about the origin of an ethnos is its language. There is much reason in the common saying that the language of the people is their history. Forming in the deepest antiquity, language, together with its carrier, goes through a complicated process of development, being mixed with the neighbor languages, enriched, influenced by them and influencing them in its turn.
History knows many examples of language mixture or assimilation of one language by another.
Nevertheless, many languages preserve their peculiarities. It is these characteristic features of the language that make language one of the most important source of ethnogenetic information. The second important source in this problem is the data of ancient writers, which may describe the territory occupied by the specific tribes or peoples, the changes in their boundaries, the ways and causes of their migration in various directions, as well as report of the mixture of different peoples, and so on. However, one must always remember that the tribes or peoples are rarely mentioned in these sources under the same name in the course of several centuries. Quite often, the chronicles speak of specific parts of the same tribes which played more important historical roles in the particular historical phase and hence get mentioned in the annals.