Final answer:
William H.R. Rivers' work constructing family trees for Torres Strait Islanders is an example of ethnography, which contributed to kinship studies and the understanding of sociocultural relationships in anthropology.
Step-by-step explanation:
William H.R. Rivers' construction of family trees to identify kinship terms used by Torres Strait Islanders is an example of ethnography. Through his methodical approach and use of the genealogical method, Rivers sought to understand the sociocultural relationships and the impact of family on those relationships in small-scale societies. His work contributed significantly to the methodical examination of kinship systems and established a basis for later anthropologists like Bronislaw Malinowski and A.R. Radcliffe-Brown to expand upon the studies of kinship as a social institution and its intersections with other societal institutions such as inheritance and politics.