• A Comparison of Methods Used for the Calibration of Radiocarbon Dates

      Aitchison, T. C.; Leese, Morven; Michczynska, Danuta J.; Mook, W. G.; Otlet, R. L.; Ottaway, B. S.; Pazdur, Mieczysław F.; van der Plicht, Johannes; Reimer, P. J.; Robinson, S. W.; et al. (Department of Geosciences, The University of Arizona, 1989-01-01)
      Current calibration methods for single and replicate 14C dates are compared. Various forms of tabular and graphic output are discussed. Results from all the methods show reasonable agreement but further methodological development and improvements in computer output are required. Comparison of existing techniques for a series of non-contemporaneous dates showed less agreement amongst participants on this issue. We recommend that calibrated dates should be presented as a combination of graphs and ranges, in preference to mean and standard deviation.
    • An Interim Progress Report on Stages 1 and 2 of the International Collaborative Program

      Scott, E. M.; Aitchison, T. C.; Harkness, D. D.; Baxter, M. S.; Cook, G. T. (Department of Geosciences, The University of Arizona, 1989-01-01)
      We report in this paper on a preliminary analysis of Stages 1 and 2 of the International Collaborative program. We have chosen to concentrate on the internal and external consistencies of the participating laboratories. The two stages so far completed have dealt only with the processes of sample synthesis and counting, and results indicate that the major component of variability lies in the counting process. Outlying laboratories are observed at each stage. A third stage is in progress which will allow an assessment of any further variability due to sample pretreatment. With the inclusion of duplicate samples in each stage, we are able to report that laboratories are remarkably consistent internally, ie, the differences between duplicates generally agree with the laboratory's claimed precision.