The main focus of this research group is the development of methods to improve today's information retrieval systems. Besides the design of the user interface itself, the focus is on the development of methods to adapt a retrieval system dynamically to the needs and interests of the user. This involves studying methods to monitor and analyse the behaviour of individual users as well as user groups to obtain information about their needs and interests. Furthermore, methods are developed that are able to use this information to reorganise the structure and the presentation of the considered document collection and search results in order to support the users in their retrieval tasks.