Introduction. The problem of studying the ethnogenesis and ethnic history of ancient and medieval peoples appeared immediately after the formation of archaeology as a science. At first, archaeologists tried to identify the bearers of archaeological cultures with specific ethnic groups, and then they began to determine cultural-historical communities and color them ethnically. In the anthropological context, cultural-historical communities exist in the form of paleopopulations or samples. The question of the relationship between the materials of the monument and the sample is legitimate since often the archaeological and anthropological contexts do not coincide. Methods and materials. The work is based on a comparison of data from an anthropological sample (paleopopulation) and cultural and chronological definitions of archaeological complexes from where the material originated. For this, both the results of studies published by the author and new data, which were studied by the methods of simple and multivariate statistics, were used. Analysis and discussion. Comparative analysis of the Sauromat-Sarmatian materials shows that the series of previous and subsequent cultures often show great similarity, which can be explained not only by the continuity of the population but also by the fact that the chronological groups are members of the same paleopopulation. In addition, there are a number of complexes of the transitional period that are culturally defined by different archaeologists in different ways. Another aspect, which is considered in the article, is connected with the materials of the same burial ground or even a mound-cemetery of the Middle and Late Bronze Age. With the relative synchronism of the burials, a different cultural interpretation (variant, culture) is given, which leads to significant difficulties in the study of anthropological materials, the results of which also allow us to assume that all individuals belong to the same population. Conclusions. The problem associated with the procedure of sampling for bioarchaeological research has a long history, and it needs to be solved in the context of the archaeological source being studied. It is necessary to constantly compare the monument data with the results of the sample study, rethink, revise, and test them, and determine how reliable they are and whether they fall into the confidence interval.