All methods considered are based on the t statistic procedure introduced by Baillie & Pilcher (1973), and are distinguished by the way the data are transformed before cross-dating.
The results show that a range of such "pre-whitening" methods can usefully be employed, and no single method is universally superior.
Since cross-dating depends on matching the high-frequency elements of a sample against a master chronology, various methods are explored for removing the low-frequency variance in ring-width series before they are compared.
The best match (lowest P value) can be compared to other matches as an additional means of assessing cross-dating strength.
Tree-ring analysis requires observation and pattern recognition.
The Laboratory of Tree-Ring Research (LTRR) at the University of Arizona played a central role in the cross-pollination of these disciplines by providing the first wood samples of exactly known age for the early testing and establishment of the "Curve of Knowns" by Willard Libby.
From the 1950s into the early 1980s, LTRR continued to contribute dated wood samples (bristlecone pine and other wood species) to 14C research and development, including the discovery and characterization of de Vries/Suess "wiggles," calibration of the 14C timescale, and a variety of tests to understand the natural variability of 14C and to refine sample treatment for maximum accuracy.
The assumption is that a particular type of artifact, for example a type of sword, when found in an undated context will bear a similar date to one found in a dated context, thus enabling the whole of the undated context to be given a chronological value.
The method is based on the assumption that typologies evolved at the same rate and in the same way over a wide area or alternatively on assumptions of diffusion.
By itself, a cross-dated chronology does not give absolute dates, but it may be calibrated by reference to other dating methods.