To solve problems of ethnogenesis it is important to know the ancestral homeland of ethnoi and places of their more recent settlements, since the formation of language and culture of people is influenced by climatic conditions and other geographical factors that determine, among other things, also the language substrate and the contacts with neighboring ethnic groups, what played great role in the whole complex of ethnogenic processes at prehistoric time. For a long time with no other reliable data, scholars were hoping that language characteristic of place names on certain territories could give reason to consider these areas as the Urheimat of the speakers of this language. However, it is also important to know the chronological framework of the appearance of place names, but they themselves don’t give the answers to this question does and therein the difficulty of its use lies. Numerous attempts to locate the Urheimat of various nations have failed because of their controversial nature and very often scholars can not convince the opponents of the fairness of their conclusions. The place name study (toponymy), really, couldn’t have probative value and gradually doubts of its use in studies began to be expressed because "… toponymic etymology is almost always conditional since it is unproved in the vast majority of cases" (MATVEYEV A.K.,1965)
In the case of the Slavs, even a paradoxical situation turned out, where, according to L. Nederle, "there is no area in Europe in general that could be considered a Slavic Urheimat, as there is no region where a geographical terminology would purely Slavic" (NIDERLE LUBORЪ., 1956: 34).
Nevertheless, it is hoped that data of toponymy can be verified by the results obtained in other ways, but having a chronological anchor. The historical developed research methods do not provide in full such opportunity, but in the second half of the 20th century, the internal development trends of the social sciences have led to the widespread use of precise, mathematical methods. This also was contributed by the development of technology, which provided for the use of powerful tools for the mathematization of science – electronic computers. Gradually, starting from the simplest processing of statistical data, special mathematical techniques have been worked out in various fields of social sciences, and systematic approach to the study of social, historical, linguistic processes even led to the development of the special sciences, synthesizing in traditional and new mathematical methods of research. An example of such a science can be mathematical linguistics, a very broad science that uses mathematical techniques of different plan. For example, a method based on mathematical graph theory is using in textual criticism to determine the authorship of the works by analyzing its vocabulary. The method called graphical-analytical is also based on building a certain type of a graph. This method is also used for processing lexical and statistical data, however not a of separate work but of the vocabulary of closely related languages. The method consists in building a graphical model (schema) relatedness of languages of one language family or group based on lexical statistics. Construction of the model is based on the law of inverse proportion between common words in pairs of related languages and the distance which their speakers resided on at the time of initial forming these languages (dialects). Then, this model is connected with a suitable place on the map where there are areas, formed by natural boundaries (rivers, mountain ranges, etc.), which restricted contacts between the populations of the whole territory and contributed to the formation of separate dialects in these areas on the basis of a common language. At first view, a suitable place could be always found for any circuit anywhere. But in reality it is very difficult to do. However, full confidence in the accuracy of the placement of schemes can not be. More evidences are need what can be provided by archeology, toponymy, linguistic substratum. If these facts do not contradict each other, then we can talk about the high reliability of results obtained while using the graph-analytical method, and archeology allows you to define the time frame of stay of different ethnic groups in certain areas.
Such comprehensive studies have allowed to accurately determine the area of formation of several tens of primary ethnic groups, most of which, under the influence of various natural and historical circumstances have evolved into the modern nation or in spite of these circumstances have kept their ethnic identity to this day. A relatively large proportion of these ethnogenic processes took place in the Ukraine at prehistoric time, and they are reflected in place names.
There are in the Ukraine thousands of names of villages, rivers, mountains, which can not be explained by means of Ukrainian. A fairly large portion of them, especially in the steppe, have Turkic origin. These place names should be considered as of relatively late time, permanent population does not remain for a long time here due to periodic invasions of nomads from the east. However, it is significant that there are in the forest-steppe zone, in the Polesie, and in the Carpathians, where the population for many centuries remained fairly stable, a lot of obviously non-Ukrainian, even non-Slavic place names. Based on the results of research according to ethnicity of the residents separate areas, an attempt was made to explain the "dark" place-names by means of the German, Iranian, Turkic and Finno-Ugric languages. Initially, nearly 1,100 place names in the forest-steppe Ukraine were analyzed using the 1:200,000 scale topographic maps and , when it was found that three-quarters of them could be fairly reliable decoding, the place names in Central Russia, the southern Belarus, south-western Poland, and north-eastern Hungary was studied too.
Place names cannot be not always connected directly with other data, and then the question of staying of an ethnic group on a certain territory is solved by comparison with reliable data on neighboring territories. For example, the Baltic place names in the basin of the of Pripiat, Desna and Seym clearly indicates that some time this territory was inhabited by the Balts. V Toporov and the O. Trubachiov consider such names of the rivers Vessia, Kovna, Luniya, Mazha, Morozha, Mytvitsa, Narovla, Nacha, Nertka, Osvitsa, Tremlia, Tsna, Shacha and many others as Baltic ones. Perhaps some of these names have Slavic origin, but in the mass, these names do not look Slavic. Other data about the presence of the Balts on these places are absent, but we know that the Urheimat of the Baltic was in another place and took a much smaller area. On the other hand, there are linguistic data about the contact of the Baltic with the Thracians, the place and the time of their settlements are known to us. Thus, we can confidently say about the migration of the Balts to the basin of the Pripiat and its chronological framework. The boundary of the Baltic and Finno-Ugric place names quite clearly delineates the boundaries of settlements of the Finno-Ugric peoples in the west of their territory before the Slavic expansion:
As a whole, the northern and eastern boundaries of the Baltic tribes of early Iron Age in the main coincide with the boundary separating the Baltic and Finno-Ugric toponymies and hydronymies. This boundary ran from the Gulf of Riga to the upper reaches of the Western Dvina and the Volga. Turning further to the south, it is cut off Riverlands of the Moscow-river from the basin the Volga river and the upper reaches of the Oka river, then along the watershed of the Oka and the upper reaches of the Don came to the steppe (TRET'YAKOV P.N., 1982: 54-55)
Many information can be given by the study of Thracian or Illyrian gydronimy that is concentrated in certain small regions. To the contrary, the analysis of the Turkic place names can give only scanty material to draw conclusions. The Turkic languages are quite conservative, so in the first place, it is difficult to make the stratigraphy of the Turkic place names, knowing that Turks inhabited some area as in ancient and in quite recent times. Secondly, the Turkic place names are spread very large area, so it is difficult to localize the primary places of Turkic settlements. Thirdly, the number Turkic people are numerous, so sometimes it is difficult to bind a certain Turkic name to a specific ethnic group. Approximately the same, but to a lesser extent, can be said about the Iranian place names. The analysis of the Slavic place names generally wound up scientists to a standstill, as evidenced by the above words L. Niderle. However, we can get a lot information by comparative analysis of place names of modern Slavic territories and their Urheimat. Though such comparisons are not always possible or very difficult. For example, the comparison of the place names of present-day Poland and the former Polish Urheimat has no sense, since the Polish influences reached far into the territory of Belarus still in fairly recent times. The same applies to the Ukrainian, Belarusian and Russian place names. The results may give a comparative study of place names of the Slavic peoples, ancestral home of which lie far from their present-day territories. This applies to the Czech and Slovak place names and place names of the South Slavs.
Often, people have moved to new lands give the same name for geographical object, they are accustomed to the old places. This is manifested particularly clearly in the comparison of modern Czech and Slovak names of settlements with place names of the Urheimat of the Czechs and Slovaks. Much less this phenomenon refers to the names of the rivers. However, despite best efforts, convincing parallels between Slavic Balkan place names and place names of the South Slavic Urheimat.
Of all the results of these studies, localization of the Turkic Urheimat in Eastern Europe excites special aversion and, in particular, the stay of the Proto-Bulgars in the Western Ukraine, and their correlation with the Scythians. But, as it was already shown, a lot of the place names of the Ukraine can be etymologized by means of the Chuvash language, though the vast majority of them does not contain any links with the natural and geographical features, which could be reflected in the proposed appellatives. In such circumstances, when random phonetic coincidence in the whole set of the alleged Scythian place names cannot be eliminated, statistics helps substantively. The concentration of etymologized names by means of Chuvash on particular area helps to determine as a primary settlement area of the ancient Scythians and ways to the later migration. Herewith, place-names located in isolation, may be regarded as a coincidence. As a whole about 330 place names were etymologized by means of the Chuvash language. Then they were divided into regions and it was found that most portion of them are located in the Lviv Region, that is 60. This is more than half of all place names of Lviv region taken for analysis, despite the fact that more than a quarter of them are not etimologized at all. Next come Cherkassy Region- 38, Vinnytsia – 32, Khmelnytsky – 32, Ternopil – 24, Poltava – 24, Zhytomyr – 17, Ivano-Frankivsk -15. Thus, the assumption about the location of the primary habitat of the ancient Scythians to the south of Volhynia was confirmed by statistical data