Schewe, Klaus-DieterKaschek, RolandMayr, Heinrich C.Liddle, Stephen2019-10-112019-10-1120053-88579-392-Xhttps://dl.gi.de/handle/20.500.12116/28346The development of web information systems has led to new challenges regarding the scalability and expressiveness of methods. In particular, as systems become large, it becomes decisive to guarantee consistency and integrity of designs. The paper introduces the challenges in a step-by-step way and indicates how to cope with them. First, the conceptual model of a WIS as a collection of media types, i.e. extended views, is introduced. In this context the adaptivity to users, channels and devices will also be discussed. Secondly, WIS development is discussed on a higher level of abstraction dealing with tasks, roles, user profiles and storyboards. At this level equational reasoning can be applied. Finally, both levels of abstraction are combined leading to further challenges by using dynamic and deontic logics.enText/Conference Paper1617-5468