Reliability classes:
Class 1: dates collected from secure cultural deposits that include wood charcoal from identified short-lived species, palm endocarps, and algal nodules;

Class 2: dates from secure cultural deposits on unidentified wood charcoal (Spriggs and Anderson’s (1993) criteria L);

Class 3: dates that are not reliable due to problems of mixed isotopic fractionation (Spriggs and
Anderson’s criteria I), dates from the Gakushuin Laboratory (Spriggs and Anderson’s criteria A), dates on coral and bone that are questionable due to calibration issues (Spriggs and Anderson’s criteria B), and dates from questionable contexts (Spriggs and Anderson’s criteria D, F, G).

Stratigraphic sub-classes:
a:  samples collected from below an architectural feature, meaning that they probably pre-date the construction of that feature (i.e., under ahu walls) (see Dye, 2009; McCoy et al., 2011); (terminus post-quem).

B: dates that are close in age to the target event, such as the activity of burning wood in an earth oven. Although the burnt wood from an earth oven will produce a date that is older than the archaeological burning event, the identification of short-lived species means that the dated sample is close in age to the target event.

c. samples recovered from cultural deposits that are not spatially and/or stratigraphically associated with an architectural feature in the landscape but are from stratigraphic layers that include other cultural materials such as portable artifacts.