|■ Relative dating techniques which identify the order in which sites or artefacts were used in a sequence from earliest to latest.|
|■ Absolute (or chronometric) dating techniques that try to establish an exact or approximate calendar date for a site or artefact.|
The techniques selected depend on the specific task and evidence as well as practical considerations such as cost. Many of the scientific techniques are expensive and require high levels of technical skill to use and to interpret. The span of human history studied by archaeologists is so vast and environments so varied that techniques suitable for one place and period may be unsuitable for another.
For sites less than 5,000 years old there may be written or artistic evidence which can provide precise dates as long as the original language can be decoded. For example, coins, seals, inscriptions and clay tablets were used by the civilisations of the Mediterranean and Middle East. Sometimes historical records such as dates, calendars or lists of rulers are available. These have allowed sites such as Egyptian