Service annotations can be exploited to significantly enhance the initial UI which is generated by the tranformation of interaction tasks into dialogs. Without annotations, the initial UI generated from a task model lacks suitable layout definitions, usability optimizations and the selection of appropriate UI controls. This is due to the fact that the task model does not contain the necessary information.
It must be added manually by a time-intense refinment of the initial UI. In case of annotated tasks, this information is contained in the UI related service annotations (see sect. II). It can therefore be automatically evaluated in the transformation process. This reduces the need and the time for a manual refinement of dialogs generated from interaction tasks associated with annotations to a minimum.
Another application area for annotations in the area of UI generation from tasks models is a better support for the grouping of interaction tasks. In our approach, one interaction task is transformed into one dialog by default. The default behaviour can be overwritten by combining interaction tasks into groups. The UI controls that are generated for all interaction tasks in a group are added to one and the same dialog, giving the developer control over the transformation result.
This simple merging approach produces dialogs that can contain duplicates, i.e. UI controls controls with identical functions, that have to be removed manually in the refinement process. A solution to avoid the manual removal of duplicates is to apply the composition operation Union proposed in  for groups of interactions tasks. The Union operation composes two dialogs into one and avoids duplicated UI controls, given that duplicates can be identified. In our case, duplicated UI controls can be identified based on annotations that describe relations between parameters of different operations. We are therefore able to provide the Union composition operation for groups of interaction tasks.
In the example in Fig. 3), the Union operation is added to the group containing Login Success and Enter Search Criteria. It guarantees that the dialog generated by the combination of the ’Welcome’ message ’search criteria’ form is free from duplicates. Again it shows that the annotations can reduce the effort for manual refinement significantly.
In this work-in-progress paper the combination of the concept of annotated services and the task-driven development approach has been proposed. We introduced the notion of annotated tasks to integrate annotated services in task models and to derive and associate interaction tasks automatically. This approach has been evaluated by extending the EMODE task model and transformations. Based on examples it has been shown how service annotations can be exploited to increase the efficiency of task modelling significantly. Furthermore, ideas have been presented to reduce the efforts for UI refinement steps by including hints for UI creation within the service annotations.
In the future we will extend our approach to complete the list of annotations usefully in the scope of our concepts. We will also improve the integration of our concepts into the EMODE tools. An in-depth analysis to qualify the amount of source code generated automatically in typical servicebased interactive applications by applying the service annotation concept is currently under consideration. The application of the service annotation concept to end-user development methodologies is currently a second parallel research focus.