This report discusses information systems as support systems for knowledge workers. A case is presented discussing the introduction of two types of information systems into an organisation as support for knowledge workers. The case is interpreted using a set of theories from knowledge theory and the area of knowledge management. The aim of this report is to give empirical input to the understanding of the conditions of knowledge work and information systems. An interpretative framework is presented consisting of a set of perspectives on knowledge work and the use of information systems.