BCal help system: The Tutorial

Step D1: Why is sensitivity analysis so important?

In adopting Bayesian radiocarbon calibration, you are using a very flexible and sensitive tool. By sensitive we mean that apparently small changes in how you represent the archaeology can have a big effect on the results you obtain. Consequently, it is very important that you carefully consider the specific representations you choose and investigate what happens when you vary them; this is called sensitivity analysis. Once you have completed an initial investigation within BCal it is essential that you undertake such analysis and that you report your findings in any publication based on this work.

Even though our tutorial is based upon a simple site, there are still many types of sensitivity analysis that can be performed. As an example, we'll consider what effect changing some of the relative prior chronological information has. In particular, we'll see what happens when we modify the group relationship between Layer III and Layer II to be just earlier, rather than abutting and earlier.

In order to make this change, we need to return to the project manager list page by selecting "Project Manager" from the BCal menu. When making modifications to a calibrated project, it is wise to make the modifications to a copy of that project. This way we will have access to both sets of results should we need them. To copy the project we should select "Copy" from the project manager list page for "The Tutorial".