User interface modeling in UMLi

Although user interfaces represent an essential part of software systems, the Unified Modeling Language )UML) seems to have been developed with little specific attention given to user interface issues. Several researchers have investigated integrating interface modeling techniques with UML. In UML, one models tasks using extended activity diagrams rather than by incorporating a completely new notation into UML. UMLi also addresses the relationships between use cases, tasks, and views, and thoroughly addresses the relationship between tasks and the data on which they act. UMLi is probably the most technically mature proposal for interface development in UML.