The systematic and scientific recovery of cultural, material remains of people as a means of obtaining data about past human activity. Excavation is digging or related types of salvage work, scientifically controlled so as to yield the maximum amount of data. It is the main tool of the archaeologist. The excavation of a site, however, involves the destruction of the primary evidence, which can never be recovered. Excavation should therefore never be undertaken lightly or without an understanding of the obligations of the excavator to the evidence he destroys. The first decision is whether to excavate a site at all, a question of particular interest when sites are being rapidly destroyed by farming methods and road and town building. The nature and scale of the undertaking is the next decision. If time and/or money is short, sampling of the site may be all that is possible. If a large-scale excavation is to be undertaken, the approach will be either area (open) excavation, grid method, quadrant method, rabotage, sondage, etc. Removal of the topsoil will either be carried out by hand or machine. After an initial plan has been made of all visible features before excavation, digging proceeds according to the dictates of the site: sections may be taken across areas of feature intersection, or across individual features. A permanent record of the whole process should be kept: plans, drawings, notes, photographs. Excavation is only the first part of the process. For years, excavation was regarded as merely a method of collecting artifacts. Pitt Rivers in Britain and Petrie in the Near East first placed emphasis on evidence rather than artifacts, not what is found but where it was found relative to the layers of deposit (stratigraphy) and to other objects (association) - the context. The excavator can only justify his destruction if it is done with meticulous care so that every artifact, be it an ax or a posthole, is discovered and if possible preserved; if it is recorded accurately enough for all information to remain available after the site has disappeared; and if this record is quickly made available by publication. In short, excavation is the digging of archaeological sites, removal of the matrix, and observance of the provenience and context of the finds therein, and the recording of them in a three-dimensional way.