Goal not to find a single site but pattern of human uses of landscape. Move around landscape for diff tasks in diff seasons. Two types given: base camp with surround smaller sites. Marsh: cyclical movement, perhaps on seasonal basis. Carry out survey to get a picture of landscape to figure out distribution of sites. If you only found a site your wouldn"t get pattern. Two types given: signature of complex societies". Large urban centre: random settlements along river. You won"t get the whole picture and create a biased view. Erosion gets built up overtime and evidence gets buried. In some cases you can use aerial photography to see things not visible on surface. Used in southern iraq as field work prohibited. System of satellites which allows ow to triangulate your precise location anywhere on earth. Lets you locate places without needing high precision maps. Useful for exploratory research in remote location. System that allows us to correlate info.