How to Make Decision Tree
Start Decision Tree Definition Editor
To make a decision tree in the easiest way you should use the Hierarchy Generation tool in Software Ideas Modeler.
You can access the tool from:
- Ribbon / Project (tab) / Generate Diagram (group) / Hierarchy Diagram (button)
- File / Project / Generate Diagram / Hierarchy Diagram
Choose Types of Diagrams and Elements
After clicking the Hierarchy Diagram button (or menu item), the Hierarchy Generation dialog will show.
For a standard decision tree, you need just some basic rectangular elements and a directed arrow connector. So we can select the following options in the drop downs on the General tab page:
- Diagram type: Flowchart Diagram
- Box: Process
- Connector: Flow
However, you can choose any other diagram and element types for boxes and connectors, if they better suit your needs.
Define the Decision Tree
The next steps of this tutorial show you how to create a simple yes-no decision tree in no time.
Enter texts of your decision tree into the Definition box below the drop-downs this way:
- 1. Start with the main question or the main decision topic of your decision tree - enter its text to the first line and press enter
- 2. Enter the other follow-up questions to indented lines - press Tab and type (or paste) the question, then press Enter and the line will be automatically indented to the same level as the previous one, so you can just type the second question.
- 3. Repeat step 2 for additional nested questions.
- 4. Enter the text of the final decisions on the last level lines.
The lines with the questions should end with question marks, the decision lines should describe results using declarative or imperative sentences. The final decision nodes can also contain the name of a result object.
When the decision tree definition is completed, you can continue with the Branches tab - just type Yes and No to separate lines in the 'Labels for branches' edit box. You can also use other terms, e.g. True and False, Correct and Incorrect, etc.
Decision Tree Layout
The Advanced tab allows you to adjust the layout of the generated tree. You should change the Connector direction to 'From parent to child'. Other settings can be unchanged unless you want to modify the default tree layout somehow. The default setting will generate a tree with its root on the top and its branches below it. However, you can generate a tree in any direction. You can also adjust the size of the boxes and the offsets between nodes in a level (Sibling offset) and between two levels (Level offset).
When you press the OK button, the decision tree diagram will be generated and added to the active project.