Unified manipulation of interaction objects: integration, augmentation, expansion and abstraction

Interface developers combine interaction elements in order to implement the User Interface of interactive software applications, using the development facilities available by a given development tool. The functional capabilities of the interface tool may significantly affect the quality of the resulting interactive software product, as well as the resources needed for further maintenance, upgrade, porting and expansion. Interaction objects play a key role in interface tools, irrespective of the nature of the interface construction technique (e.g. graphical construction, programming language, declarative specification, task notation). We have identified four fundamental categories of mechanisms for manipulating interaction objects in interface tools. Their merits in the context of interface development tools are identified, particularly in the context of developments for diverse user groups and openness for different interaction technologies. We will also show that these two functional requirements play a key role towards meeting the objectives of User Interfaces for All.