BCal is an on-line Bayesian radiocarbon calibration tool hosted by the Department of Probability and Statistics at the University of Sheffield. We offer an easy to use on-line resource that allows researchers from around the world to make use of an integrated framework in which to interpret radiocarbon data and a priori chronological information.
This software is designed for use by researchers already familiar with the radiocarbon dating and calibration process. The software has a step-by-step, user-friendly interface, but you will still be expected to decide how your data, ideas and knowledge are represented. This means that the results you get are based on information that has been elicited from you and that you will need to explain the information that you give to others (especially if you plan to use the results in a peer reviewed publication).
All of the Bayesian statistical models and methods implemented in BCal are documented in widely available, refereed literature and are reviewed in Chapter 9 of The Bayesian Approach to Interpreting Archaeological Data by Caitlin E. Buck, William G. Cavanagh and Clifford D. Litton. If you feel that you need to read some more to familiarize yourself with the details of radiocarbon calibration, please see the texts listed in the bibliography section of the general BCal information page or visit the Radiocarbon WEB-info site hosted by the Waikato Radiocarbon Dating Laboratory.
When you write up results arising from BCal, please cite us correctly. Please give the URL for the service (as http://bcal.sheffield.ac.uk) and also cite the paper that launched the service: Buck C.E., Christen J.A. and James G.N. (1999). BCal: an on- line Bayesian radiocarbon calibration tool. Internet Archaeology, 7. (http://intarch.ac.uk/journal/issue7/buck/).
The BCal team currently comprises Caitlin Buck, Geoff Boden, Andrés Christen and Gary James. We are happy to receive comments and suggestions for improvements to the service and are always keen to hear from programmers with C++ skills who would like to help with this work. Members of the user community with "always-on" unix boxes can help host the service by running a simple to install BCal client on their own machines. For information on how to help in this way, please contact Geoff Boden.
We have recently moved BCal from a single aging server onto a network of modern PCs running Linux. We are sorry for any inconvenience caused, but there are major compensations! First, the network of processors provide a much faster calibration service than we were able to offer before. Second, the hardware problems that we were having are now resolved. Third, we now have a service that is much easier to support and a team of volunteers helping with that support and so BCal seems likely to be around for many years to come!
This resource is provided by a team of volunteers whose work is supported by charitable donations from users and others interested in our work. We make no direct charge to those wishing to use BCal for entirely academic purposes, but all institutions, companies and individuals who use this software for commercial use are expected to help fund the project and should contact the team (via Caitlin Buck).
We ask that ALL users consider making a donation to the project. US tax payers wishing to make tax deductible donations should use the form available here all other donors (including UK tax payers with Give as You Earn or Gift Aid donations) should use the form available here. All donors are asked to send a letter accompanying their form making it clear that they wish the donation to be used solely for the BCal project.