Archaeology the study of human cultures through the recovery, documentation and analysis of material remains and environmental data, including architecture, artefacts, biofacts, human remains, and landscapes.The goals of archaeology are to document and explain the origins and development of human culture, understand culture history, chronicle cultural evolution, and study human behavior and ecology, for both prehistoric and historic societies. It is considered, in North America, to be one of the four sub-fields of anthropology. There is still a tremendous emphasis in the practice of archaeology on field techniques and methodologies. These include the tasks of surveying areas in order to find new sites, excavating sites in order to unearth the cultural remains therein, and classification and preservation techniques in order to analyse and keep these remains. Every phase of this process can be a source of information. The academic goals of archaeology are not universally agreed upon, and there are at least three broad, distinct theories of exactly what archaeological research should do. (These are beyond the scope of the present discussion, but are discussed below. See also Archaeological theory.) Nevertheless, there is much common ground.