Information services are economic and organizational activities for informing people. Because informing is changing rapidly under the influence of internet-technologies, this book presents in Chapter 1 fundamental notions of information and knowledge, based on philosopher C.W. Churchman's inquiring systems. This results in the identification of three product-oriented design theory aspects: content, use value and revenue. Chapter 2 describes how one can cope with these aspects by presenting process-oriented design theory. Both design theory insights are applied in chapters on information...