The tree control is used to display a hierarchical set of data which is grouped into nodes. It contains expand and collapse icons to enable users to show or hide the children of a node.
- Provide a search control if the tree has more than 10 nodes and leaves. Users tend to have more difficulties finding items in hierarchical lists than in flat lists.
- Make sure that child nodes or leafs are part of only one parent in the tree.
- Try to reduce levels of hierarchy where possible.
- Don’t show more than 5 levels in your tree.