In the archaeology of part-literate societies, dating may be said to operate on two levels: the absolute exactness found in political history or 'history event-by-event', and the less precise or relative chronology, as found in social and economic history, where life can be seen to change with less precision over time.
The contrast might also be drawn between two 'dimensions', the historical, and the archaeological, corresponding roughly to the short-term and long-term history envisaged by Fernand Braudel.
Artefacts often have a distinctive style or design, which developed over a period of time.
In archaeology, the gradual changes in motifs were exploited systematically as a dating method by researchers from Montelius onwards.
Typological dating may foster the tendency to assume that each step in development is of about the same time length, but this does not need to be the case in reality.
All living organic materials contain Carbon-14 atoms in a constant number.
It is the only method that can be used to date rocks, pottery and minerals for dates that are approximately between 300 to 10,000 years old.
Based on a discipline of geology called stratigraphy, rock layers are used to decipher the sequence of historical geological events.
The isotope of Potassium-40, which has a half-life of 1.25 Billion years, can be used for such long measurements.
Another absolute dating method is thermoluminescence, which dates the last time an item was heated.
Relative techniques can determine the sequence of events but not the precise date of an event, making these methods unreliable.
b) Absolute These methods are based on calculating the date of artefacts in a more precise way using different attributes of materials.