Without the ability to date archaeological sites and specific contexts within them, archaeologists would be unable to study cultural change and continuity over time. No wonder, then, that so much effort has been devoted to developing increasingly sophisticated and precise methods for determining when events happened in the past.
In archaeology, dating techniques fall into two broad categories: chronometric (sometimes called “absolute”) and relative.
Chronometric dating techniques produce a specific chronological date or date range for some event in the past. For example, the results of dendrochronology (tree-ring) analysis may tell us that a particular roof beam was from a tree chopped down in A.D. 1262.
Relative dating techniques, on the other hand, provide only the relative order in which events took place. For example, the stratum, or layer, in which an artifact is found in an ancient structure may make it clear that the artifact was deposited sometime after people stopped living in the structure but before the roof collapsed. However, the stratigraphic position alone cannot tell us the exact date.