2.5. Use of the BayesianModeling

We described the use of the BayesianModeling to implements the 2SP IRT model to the data of MathData.dat described in the previous section. For more details of this application, review Bazán, Branco and Bolfarine (2006).

2.5.1 Generate the syntax of the model

1. Go to File > Open

2. Open the file with the data set.

3. Click Item Response Theory

4. This will open the dialogue box “Item Response Data”.

5. Then select the items that will be used. As well as to indicate if will use all the data or only a part of them.

In our case will select all the variables as items and then click in All.

6. Then click in Models to open the dialogue box “Item Response Theory”. Here have to select the models that will be used, in this example only select the 2SP model and click OK.

7. This generates two data files: the file with the syntax of the model chosen in WinBUGS (Skew Probit 2SP Model) and another file with the syntax of the data. (Item Response Data).

BayesianModeling generates two files, one that contains the model of Binary regression with the link selected and another file that contains the data set. Both files in format txt have to be saved to be opened in the program WinBUGS or OpenBUGS to do the appropriate analysis of Bayesian inference.