. Interaction of users with computational devices has to meet the users intention on one side and needs to be specified in a formal manner which can be uniquely interpreted by computers. Thus, we need a model of interaction which meets the intensional understanding of users and which has an extensional description that is directly implementable. In this paper we develop a model for interaction on the basis of the notion of interaction objects. We show further how this notion can be specialized to internet-based interaction. In the later case we use media objects for interaction. 1 Introduction Interaction and information both are buzzwords of everyday's life. In our understanding, information, as processed by humans, is data perceived or noticed, selected and organized by its receiver, because of his/her subjective human interests, originating from his/her instincts, feelings, experience, intuition, common sense, values, beliefs, personal knowledge, or wisdom, simultaneously...

Due to the development of the internet and cable nets information services are going to be widely used. On the basis of projects for the development of information services like regional information services or shopping services we develop a method for the creation of information systems and services to be used through different nets. The approach is based on the codesign of data, dialogues and presentations. The main concepts are information units and information containers. These basic concepts for information services are presented in this paper. Information units are defined by generalized views with enabled functions for retrieving, summarizing and restructuring of information. Information containers are used for transfering information to users according to their current needs and the corresponding dialogue step. Size and presentation of information containers depend on the restrictions of the users environment.

Existing design methods for information services include a number of gaps, which significantly reduce design productivity. We present these gaps and illustrate specific problems that arise. Particularly, we rise questions that need to be answered in order to improve quantitative and qualitative outcomes of the design process. In selected cases, we indicate possible approaches that are currently under development in our co-design project. 1 Motivation The rapid growth of the global communication infrastructure has greatly improved the accessibility to computer-based information services. However, looking for these systems discloses poor results. Surprisingly few public systems with a reasonable, non-trivial functionality do actually exist. If they do exist, the lack of methodological development often is evident. Restricted-access ("intranet") applications, which are under construction in many organizations, show similar difficulties. Apparently, the state of the infrastructure ...

Interaction of users with computational devices has to meet the users intention on one side and needs to be specified in a formal manner which can be uniquely interpreted by computers. Thus, we need a model of interaction which meets the intensional understanding of users and which has an extensional description that is directly implementable. In this paper we develop a model for interaction on the basis of the notion of interaction objects. We show further how this notion can be specialized to internet-based interaction. In the later case we use media objects for interaction.