Archaeology (also spelled archeology) is the subfield of anthropology that studies the human past through the physical remains of past human activities. The archaeological record of the human past is made up of portable artifacts, features such as the remains of buildings and structures, and ecofacts such as remains of animals and plants. When preserved in sites, they may be distributed in a three-dimensional space and associated with other remains in meaningful physical contexts such as ash layers of human origin or geological deposits. The practice of archaeology involves the observation, analysis, and interpretation of the archaeological record. Archaeological methods include pedestrian surveys, excavations, remote sensing, laboratory analysis, and the use of written documents and oral traditions. The goals of archaeology are to reconstruct past lifeways, to document and construct the histories of past cultures and societies, and to interpret and explain the human past. Several varieties of archaeology include prehistoric archaeology, which focuses on the time period extending from the first traces of hominid behavior through more than a million years of cultural evolution until the emergence of written records; historical archaeology, which focuses on the modern world of the last 500 years; archaeologies of ancient civilizations such as Egyptology and Assyriology; classical archaeology, which focuses on ancient Greek and Roman Civilizations; biblical archaeology; and industrial archaeology, which focuses on the Industrial Revolution and the archaeology of industry. Our departmental strengths are in prehistoric and historical archaeology. Regionally, our faculty focus on North America, the Pacific, and Southern Africa.