Manual

• Introduction
• Licence
• Installation
• Input of information
• Analysis
• Calibration Curves
• Viewing output
• Command reference
• Program development history
• References and bibliography
• Acknowledgements

Web interface build number:
(c) Christopher Bronk Ramsey

References

• Bronk Ramsey 1994 (first release notice)
• Bronk Ramsey 1995 (main introduction to program)
• Bronk Ramsey 1998 (approach and plans)
• Bronk Ramsey 2001 (developments 1995-2001)
• Bronk Ramsey et al. 2001 (D_Sequence method and tests of other methods)
• Bronk Ramsey 2008 (deposition models) [pre-print]
• Bronk Ramsey 2009a (new features of OxCal4)
• Bronk Ramsey 2009b (outlier analysis) [pre-print]
• Bronk Ramsey et al. 2010
• Lee and Bronk Ramsey 2012 (trapezoidal models)
• Radiocarbon Vol 55(4) (IntCal13 special issue)
• Bronk Ramsey and Lee 2013 (variable k in P_Sequence and other developments)
• Bronk Ramsey 2017 KDE plots and models
• Radiocarbon IntCal20 special issue
  • Statistical approach (Heaton et al. 2020)
  • IntCal20: Northern Hemisphere (Reimer et al. 2020)
  • SHCal20: Southern Hemisphere (Hogg et al. 2020)
  • Marine20 - Modelled ocean average (Heaton et al. 2020)

If you use this program, you should quote the reference for the calibration curve used, the version of OxCal (with any non-standard options set) and the reference Bronk Ramsey 2009a. If you are wiggle-matching tree-ring sequences you should quote Bronk Ramsey et al. 2001. For deposition models Bronk Ramsey 2008 should be referenced, together with Bronk Ramsey and Lee 2013 for variable k, and for outlier analysis Bronk Ramsey 2009b. For use of trapezoidal priors please quote Lee and Bronk Ramsey 2012. Finally for KDE plots and models use the reference for Bronk Ramsey 2017.

Introduction

OxCal is a program designed for the analysis of chronological information.

• The calculation of probable age ranges for scientifically dated samples (through radiocarbon calibration, sapwood estimates etc.)
• The analysis of groups of events which are related either through generic groupings or through stratigraphic relationships

Getting started

When you first call up the OxCal site you will be prompted for a username and password. If you do not already have one, press [New User] and fill in your initials, surname and email address. A password will be emailed to you. See the installation instructions for more details.

Once you have entered your email and password you will be presented with a dialog offering you four options:

• New project - for setting up a new project which will open the OxCal input window
• Open project - to open and old project which will give you a file dialog
• Calibrate - to do a simple single calibration
• View curve - to view a calibration curve

At any later stage the same operations can be done using either the [File > New], [File > Open] or the [Calibrate] button from the top menu.

Program structure

The program is designed in a modular way for maximum flexibility. There are two main elements.

• The analysis module (OxCalWin/OxCalMac/OxCalLinux) is the core of the program. This program is a command line based program complied from C++ source code which takes the CQL2 input file and generates three output files: one text file summarising the results, one tab delimited file suitable for integration into databases or pasting into a spreadsheet and an ECMAScript (Javascript) file which contains all of the output data.
• The web-based graphical user interface (GUI) which has a number of movable, resizable windows and is the main way of interacting with the program:
  • The input window is designed to help with the specification of chronological information. This is designed to help with the setting up of formal Chronological Query Language (CQL2) code for the analysis stage. The program allows three 'Views' of the input code two of which give a visual representation of the code and the third which allows the code to be directly edited. The interface allows the code generated to be sent directly to the analysis program either by pressing the [Run] button or using the [File > Run] menu at the top level or in the input window menu.
  • The table window shows the output of the program in tabular form and also allows you to select different kinds of report and plot.
  • The OxCal plot window shows the output of the program allows you to see the chronological plots.
  • The OxPlot Plot window is primarily used for plotting data on maps but also for some age-depth related plots.
  • The Report window shows summary information such as model schema, raw data, and outlier analysis.

You can switch between the different windows in three ways:

• By clicking on them within the interface (assuming you can see them).
• By selecting them from the window navigation bar along the bottom if they are hidden or minimised.
• By using the top level [View] menu to show the main windows if they have been closed, minimised or have been hidden.

Each window has three control buttons. These are for:

• To close the window.
• To minimise the window.
• To maximise the window.

Windows can be resized by dragging the bottom right corner of the window.

Warning

The Bayesian analysis part of this program provides the ability to perform calculation based on complex models. It is possible to create models which may bias your data in ways you do not intend (see, for example, Steier and Rom 2000 and comments (Bronk Ramsey 2000) on that paper). In particular the use of 'Boundaries' is very important where there are many poorly distinguished data-points. If you are unsure about your models please ask for advice, either from an experienced user of the program, or the author, or join the OxCal discussion group.

Licence

This software is freeware - that is it can be downloaded, distributed as a whole, and used free of change.

While every effort has been made to ensure that the program works as it should, it is provided without warranties of any kind, either expressed or implied. Should the program prove defective, you will assume the cost of any corrective action. In no event will any copyright holder be liable to you for damages, including any general, special, incidental or consequential damages arising out of the use or inability to use the program.

For further help or information join the OxCal discussion group or contact the author:

Christopher Bronk Ramsey
Research Lab for Archaeology and the History of Art
1 South Parks Road
Oxford OX1 3TG
UK