As operators can have inner operators and each operator except the root operator is enclosed within another operator the natural representation of an experiment is a tree. If you have used the Wizard, you see your experiment on the left side. If you did not use the Wizard you see an empty experiment consisting only of an empty operator chain. Figure 3 shows this main experiment view which is called ``tree view''.
By clicking on the XML tab you see the XML configuration file that describes your experiment (figure 4). If you like you can always edit it by hand using your favorite text editor. For more information about the XML configuration files see the YALE Tutorial. Selecting the Box tab shows a nicer box representation of your experiment you already know from the Wizard. You can use this view for printing. Clicking on Tree brings you back to the tree view.