Hierarchical window organization supports users structuring their work environment according to tasks. The hierarchical organization of windows allows users to map their task hierarchy onto the nested rectangle tree structure.
Figure 1 displays the mail-tool application written using elastic windows principles. The new messages are shown iconized in the left window. Old messages are displayed as icons, grouped hierarchically in separate windows on the right. The hierarchical layout clearly indicates the semantic relationship between the contents of the windows by the spatial cues in the organization of windows. The layout provides the user with an overview of all correspondence, where users can pick any category and work on it.
Figure 1: Mail-tool application: Organization of correspondence in a hierarchical layout gives the user an overview.