This animation illustrates how certain parts of the distribution (the area under the black line) are more or less likely to represent when the dated event occurred. As mentioned, the true radiocarbon date can fall anywhere under the distribution. Run the animation again and notice that the blue dashed line starts at the top and moves down; the gray colored areas expend to include more and more of the distribution as the dashed line descends, until 100% of the distribution is colored gray. If you pause the animation when it is around 60% or 70% you can see that there are four areas under the curve that are shaded gray. There is a 60-70% likelihood that the true date falls within one of those four ranges. Many archeologists choose to simplify the radiocarbon date to its median number, and this illustrates the error in assuming this—the median may be in an area of the distribution with a low probability of being the true date. Animation by Maarten Blaauw, Department of Archaeology and Palaeoecology, School of Natural and Built Environment, Queen's University Belfast.
Close Window
University of Texas at Austin
College of Liberal Arts