4.3.  Related Work 57 4.3   Related Work This section shows relations of the X’treme Prototype approach to other methods. The initial phase of our approach, understanding the user domain, focuses on gain- ing knowledge from users, most similar to contextual design [ Beyer and Holtzblatt 1998 ] .  User involvement has also been recognized in business and industry.  Eric von Hippel suggests to replace “the manufacturer-as-innovator assumption with the view of the innovation process as predictably distributed across users, manufactur- ers, suppliers, and others.” [ v. Hippel 1988 ] . We address this issue by involving various stakeholders in the second phase: understanding the domain. The third step, distilling opportunities, may include scenarios, as suggested by [ Car- roll 2000 ] , but the result has to go clearly beyond current practices. We are aware that prototyping is a key activity within the design of interactive systems. Participa- tory design [ Ehn and Kyng 1992 ] [ Muller 1992 ] , user-centered design [ Nielsen 1993 ] , and software engineering [ Tripp and Bichelmeyer 1989 ] have a tradition of using prototypes.  Moreover, literature also reports on prototypes for di erent audiences [ Wagner 1990 ] [ Erickson 1995 ] and di erent levels of fidelity [ Wong 1992 ] [ Liu and Khooshabeh 2003 ] [ Rudd et al. 1996 ] , Our approach distinguishes itself from those above, as it does not aim at trying to meet the user’s immediate needs in the course of several iterations.  We do not use prototypes as a tool for communicating and matching the developers understanding with  the  implementation  of  the  user’s  immediate  needs.   Instead,  with  X’treme Prototyping we intend to provoke and stimulate the user.  On purpose, the prototype should mismatch the users’ expectations but go beyond them.  This should enable the user to leave his ‘comfort zone’ of known practices and to extrapolate further and  beyond.   Instead  of  putting  the  user  into  a  reacting  role,  obtaining  feedback about what is good or bad as proposed by user-centered design [ Norman and Draper 1986 ] ,  the  X’treme Prototype  should  help  the  user  to  abstract  from  current  work practices  and  to  become  active  in  generating  more  innovative  ideas.   Similar  to experience prototyping [ Buchenau and Suri 2000 ] the X’treme Prototype facilitates the exploration of possible solutions and ideas.  However, the main di erence is that the  developer  are  ahead  of  users  and  expose  a  stimulating  prototype  first.   As  in participatory design [ Greenbaum and Kyng 1991 ] [ Muller, M. J. and Kuhn, S. 1993 ] [ Schuler  and  Namioka  1993 ] we  empower  the  user  to  actively  propose  alternative designs.  However, we intend to overcome the users short-term focus constrained by his immediate needs and belief in his current work practices.  The X’treme Prototype shall lead the user-developer discussion onwards to real innovative solutions instead of incremental short-term solutions. Then, within the course of several iterations, the initial provocative concept will be shaped towards a more realistic implementation with the help of the users’ more realistic assessment.  The initial activation energy, though, stems from the developers.