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.

Do

• 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

• Don’t show more than 5 levels in your tree.