The style of the artefact and its archaeology location stratigraphically are required to arrive at a relative date.
The shape and style of an artefact changes through time although its function may remain the same.
The changing styles of pottery, glass, stoneware, and metal objects provide archaeology analysts with known progressive sequences.
Since 1950 there has been a transformation in the dating techniques of archaeologists.
Absolute dating is highly dependant on laboratory analysis.
Simply assuming that an artefact is older because it was found at a lower depth in the record is only subjective science.