A tree on the left 2

• A tree typically provides poor navigational clues - does not tell where the user is now, what is clicked, and what is open. To provide all these clues, a software developer spends a lot of energy.
• A tree helps software developers put artifacts as in the systems model. This model is usually very different from the user's mental model.
• The tree typically takes more than 20% of screen space. This amount of space for navigating from one point to another is a waste of precious screen area.
• Software developers believe that each "leaf node" in the tree must be associated with a corresponding screen. These corresponding screens typically dont contain any content and are shown blank or with content that users never need.