Abstract
User involvement has, during recent years, become something of a mantra among product development managers. However, the existing literature has not much to say about how the individual user contributes to product innovation and whether her or his contribution is valuable. The thesis attempts to fill this gap in knowledge by reporting experiments in which ordinary users are asked to suggest new services that their mobile telephones could deliver. The originality, user value, and the feasibility of their suggestions are then compared to the suggestions of professional product designers. On the whole, the users contribute ideas that are more original, and that could result in services of higher user value than the professionals. Exactly how the users are involved matters for the outcome of their involvement. Two different approaches to involving users are identified, Guided Users and Pioneering Users. The Guided User approach seems to be preferable when stepwise refinement of an existing service is desired. The Pioneering User approach is better suited to supporting radical innovation. The conclusion is that firms must adapt their processes of developing new products in order to realise the full potential of user involvement.