Fig. 1. Designing alternative artifacts for the Link dialogue task. Se is used to indicate ‘empty’ (i.e. no load confirmation dialogue supported). S5 is the typical manual link targeting GUI dialogue through the mouse.

Fig. 2. Basic task operators in the Unified User Interface design method.

Fig. 3. The polymorphic task hierarchy concept, where alternative decomposition ‘styles’ are supported (upper part), and an exemplary polymorphic decomposition, which includes physical design annotation (lower part).

Fig. 4. A design scenario for alternative concurrent sub-dialogues, in order to perform a single task (i.e. task multimodality for file management).

Fig. 5. Two ways for representing design alternatives when designing for task-level multimodality: (a) via polymorphism, adding run-time control on pattern activation (top version); and (b) via the or operator, hard-coding the two alternatives in a single task implementation (bottom version).

Fig. 6. The three artifact categories in the Unified User Interface design method, for which polymorphism may be applied, and how they relate to each other.

Fig. 7. Representation of alternative physical artifacts: (A) in the case of the same non-polymorphic task; and (B) in the case where polymorphic task decomposition is needed.

Fig. 8. The polymorphic task decomposition process in the Unified User Interface design method.

Fig. 9. An example of a user-profile, as a collection of values from the value domains of user-attributes, extended from Stephanidis et al. (1997).

Fig. 10. Design relationships among alternative styles, and their run-time interpretation.

Fig. 11. An example of recording design documentation.

Fig. 12. Relationships among alternative styles of Link Selection task.

Fig. 13. Designed styles for the Page Loading Control task.

Fig. 14. Relationships between designed styles for Page Loading Control task.

Fig. 15. The Link Summary styles: S1, (top) and S2 (bottom) for Page Browsing task.

Fig. 16. Three different interface versions of the AVANTI browser produced by adaptation-oriented selection of different alternative styles.

Fig. 17. Alternative augmentation-oriented styles for motor-impaired user access activated at run-time in the AVANTI browser.