Archeologists make informed decisions about where to investigate. They begin by using:
- Above-ground, noninvasive techniques
- Minimally-disturbing, invasive techniques
Above-ground, Noninvasive Techniques
- Predictive Models
Predictive site models assume patterns of human settlement for any particular time period in a particular environment. They begin with a hypothesized pattern drawn from known site locations and analogies with ethnographically known societies. Confirmation is then sought through site discovery and inventory.
- Archival Research
Archival research includes text-based sources, such as documents, government documents, maps, journals, photographs, and tax records. Fieldwork may confirm or conflict with archival sources.
- Oral Histories
Oral history is historical tradition passed by word of mouth. Oral histories may consist of a person’s memories about past experiences, or knowledge or traditions passed from one generation to the next. Oral histories are the basis of cultural identity and knowledge for many groups and are a key element in understanding that group’s experiences, perspectives, and culture.
- Surface Inspection
“Reconnaissance,” “above-ground survey,” or “walkover” surface inspection is when a archeologists walk systematically, in a purposefully regular way over an area, recording and/or collecting structures and artifacts from the surface only.
- Geophysical Prospecting or Remote Sensing
Remote sensing identifies archeological features buried below ground that still leave their mark on the landscape. Techniques include: aerial photography, aerial infrared photography, imaging radar, electrical resistivity, electromagnetic surveys (also known as metal detecting), ground penetrating radar (GPR), magnetic prospecting, Geographic Information System (GIS), Global Positioning System (GPS)
- Previous Excavation
When archeologists have excavated a place, or a similar place, before, they may have ideas about where else sites can be found. Archeologists may consult reports or other archeologists to decide where to look next.
Minimally-disturbing, Invasive Techniques
- Archeological Surveys
Archeological surveys identify all or a sample of the archeological resources in a given study area. Site testing or evaluation focuses on extracting information about the size, contents, and structure of an archeological site, a portion of a site, a number of related sites, or, perhaps, the spatial distribution of archeological remains within an area.
Sampling investigates a portion of an overall area. Sampling methods may be judgmental, that is, based upon past knowledge or present interpretations, or probability-based, that is with sample units selected mathematically, or a combined method may be used that combines judgement with probability.