The navigational aspects of the logical design of user interfaces

The design of the user interface (UI) involves: a) logical design of the UI; and b) perceptual design of the UI. The logical design of a user interface includes both static or data related and dynamic or navigational aspects. The static aspects were discussed previously (E.J. Chang and T.S. Dillon, 1997). An important part of the static design is the determination of abstract user interface (AUI) objects. These abstract interface objects contain all of the information related to carrying out: (i) entry and display of information; (ii) actions that need to be taken by the user to move to another AUI object or window; (iii) actions to initiate or stop an action within the system. They do not however, contain information on the set of preconditions that must hold before a particular action under (ii) or (iii) above can be taken. Nor do they contain information on the set of post conditions that apply after the action is taken. These preconditions and post conditions, when chained together, specify the sequencing of events between the AUI objects. We define the Flow of Interaction Nets (FIN) which provide information related to this sequencing. These nets define the Flow of Interaction between the user and the system.