Patterns for Task- and Dialog-Modeling Maik Wurdel 1 , Peter Forbrig 1 , T. Radhakrishnan 2 , Daniel Sinnig 2 1 Software Engineering Group, Department of Computer Science, University of Rostock Albert-Einstein-Str. 21, 18051 Rostock, Germany {maik.wurdel, pforbrig}@informatik.uni-rostock.de 2 Department of Computer Science, Concordia University, 1455 De Maisonneuve Blvd. West, H3G 1M8, Montreal, Canada {krishnan, seffah, d_sinnig}@cs.concordia.ca Abstract. The term Context of Use has been treated with much attention in HCI in recent years. In this paper, the integration of context information into task models will be described. The notion of context is formulated and used to annotate the task model. The reuse of such context-sensitive task models in light of task patterns is also examined. Keywords: task modeling, context-sensitivity, task patterns, context of use 1 Introduction The development of UIs is complex and requires the integration of different disciplines. Model-based UI development has gained much attention by various researchers [5, 6, 8, 9], due to its ability to foster the integration of different viewpoints into the development process in the early stages of the development process. In general it tackles the problem of UI development by using different declarative models and the relationships between these models. The task model as a description of the tasks and goals is a commonly accepted starting point for model- based UI development processes. Other models that have to be taken into account describe the environmental circumstances of the execution of tasks. The Context of Use (CoU) as an abstraction of these circumstances influences the tasks a user has to fulfill. Note that some tasks might not be useful or possible in a certain context. The adaptation of the UI according to the context can improve the human computer interaction by providing an adapted UI for the specific CoU. In this paper, we will demonstrate how context models are integrated into a model- based UI development process, with particular emphasis on the task model. A definition of the term context and a formalization is given, which is later used to enrich task models. Finally we illustrate how context sensitive task patterns can be used as building blocks for the creation of context sensitive task models. The idea of reuse of generic model fragments by means of the use of patterns will be illustrated.