Instructions on how to write and run models are specified in the WinBUGS (openBUGS)help file. The open population scripts are for winBUGS. The closed population scripts are for openBUGS. All models specified have a separate file for the model, data and initial values (if used). A script file is also specified. To run the script file from the drop down menu select: Model>Script The script will automatically include the data, compile the model, monitor the nodes and begin running the model. NOTE In order for the DD model to run in WinBUGS 1.4 two of default samplers need to be changed: 1. The updater for "logistic RE" needs to change to UpdaterSlice. 2. The updater for "log concave" needs to change to UpdaterSlice. The description of how to change the defaults can be found in the WinBUGS help file under "changing MCMC defaults". Two alternatives to using WinBUGS 1.4 for the DD model are: 1. To use OpenBUGS 2.2.0. We have experienced problems with the latest version (v3.0.3) for this problem and do not recommend it. 2. To use JAGS. Before using JAGS the differences between JAGS and WinBUGS need to be understood. Of particular importance is the difference in how the data (and init) files are structured.