• The structural, static aspects of the interface objects using composition
• The way in which interface objects are statically related with navigation objects
    – Use Configuration Diagrams to express these relationships
• How they behave when reacting to external events;How they trigger navigation and which interface transformations occur
    – ADV-charts used
            • Allow to specify different states of interface objects
            • The relationships between external events and the transitions shown
            • Can be enriched with a Petri-net like notation that allows expressing simple synchronization of concurrent activities