The distinction between radiocarbon years and calibrated calendar years is particularly important when comparing the Paisley dates to the conventional Clovis horizon, which is also expressed in calibrated calendar years.

The approximately 1,000-year difference between the oldest Paisley dates and the conventional Clovis horizon is expressed in calibrated calendar years, not radiocarbon years.

Making this comparison correctly requires converting all dates to the same temporal framework — calibrated calendar years before present — before drawing conclusions about their relative positions in time.

The 2012 Jenkins paper used a dense program of radiocarbon dates to build what is effectively a Bayesian chronological model of the site’s occupation sequence — a model that uses the stratigraphic order of the samples (older samples should be below younger samples in an undisturbed sequence) and the radiocarbon dates to produce refined probability distributions for the age of each phase of occupation.

This approach produces more precise and more reliable age estimates than simple one-date-at-a-time comparisons, and it allows researchers to assess the consistency of the dates with the stratigraphic sequence — identifying any anomalies that might indicate disturbance.