I’ve already written about my systems-led approach to accessibility research. This series of articles is designed to put a little more flesh on the bone with a detailed look at how OOA/OOD (Object Oriented Analysis and Design) can be used to describe computer systems and their interaction with users.
2.4 Abstract User Interfaces
The Shlaer and Mellor method makes direct reference to user interfaces, and proposes use of an abstract user interface within an appropriate ontology. Counterparts are then identified between client domains and the user interface. For example, a mobile telephone generally requires a user-edited (but not created) phone/address book, which itself requires some form of user interface. In Shlaer Mellor this would b drawn as a Domain Chart (DC) similar to that shown in Figure 1 below.
Figure 1 shows three related ontologies; an application domain expressing users accessing contact details, an address book domain expressing the organization of contact details, and a user interface domain expressing perhaps text, icons and radio buttons. The bridge between the AddressBook domain and the UserInterface domain describes the mapping of icons to photos and text to data fields, and so on. Such a bridge is an explicit concrete reification of the encounter between a user and a mobile phone.
Of interest here is why those mapping are chosen in the general case, given a specific user and context. The fact that the Shlaer and Mellor method already considers and expresses specific concrete cases further supported the selection of the method.
Next: Competition for resources