The approximately 7,000 languages spoken in the world today are classified into several systems known as language families, and the systemic relationships among these various language families can be delineated with systemic (genealogical) maps. Language families and systemic relationships in their original definition are determined by whether it can be proven through the comparative method that they share a common ancestor language (founder language). Systematic classification of actual languages can also receive clues from characteristics based on typological theory and geographical divisions, historical records, and other characteristics.

The objectives of this research will be as follows: (1) to seek what the latest systemic classifications are, and what techniques and what methods are employed in discussing systemic relationships; (2) to seek the appropriateness of the methods discussed in item 1, and the feasibility of their application to other language families; (3) to understand the current situation about implication of the systematic classification of languages in prehistorical and historical research in various regions, verifying and generalizing the methodology for searching more scientific methods for language classification research with a higher degree of universal applicability; and (4) to seek to discover a way to relate these results to research concerning language prehistory and history.