The user interface of data-intensive information systems may be described as a collection of semi-independent dialogues with underlying procedures accessing databases. It will be shown how to conceptualize dialogues via dialogue objects. These are organized in an object oriented fashion by dialogue classes modelled as extended database views. The description is based on an object oriented model which enables a smooth integration of dialogues with the underlying database schema. The resulting integrated model can serve as a unifying conceptual umbrella encompassing both databases and user-interfaces. The only remaining task for the presentation layer consists of suitable ergonomic presentations of dialogue objects on the screen by means of a general user interface management system. This approach may help in the development of information systems that aim at the support of highly skilled users. The design of such systems has to cope with the specific work conditions as being self-organized, equipped with certain duties and responsibilities and dependent on some environmental knowledge. Such systems are supposed to leave fundamental decisions to their users, e.g. to continue or interrupt a certain piece of work or to switch from one application to another in order to achieve a seamless embedding in organisational processes and work flow.