A pattern approach to specifying usability features in use cases

Functional features like Undo can greatly add to the usability of interactive software systems. In recent years, many features have consequently been identified as usability patterns --- proven and reusable solutions for building usable systems. This paper presents an approach to integrating usability patterns into established software engineering processes, mainly requirements definition. The approach uses semiformal specification templates to enable developers to specify pattern application in use case-based requirements specifications. Both general constraints for pattern application and low-level requirements related to individual interactions between a system and its users can be specified. The resulting specification defines how and where usability patterns are to be applied, thus facilitating subsequent engineering activities (e. g. software architecture design, implementation, and test) and improving traceability of pattern application.