Users and other figures can become part of the design process as expert of their experience, but in order to take on this role they must be given appropriate tools for expressing themselves. The designers should provide ways for people to engage with each other as well as instruments to communicate, be creative, share insights and envision their own ideas. The co-design activities can support different levels of participation, from situation in which the external figures are involved just in specific moments to situations in which they take part to the entire process, building up the service together with the designers.

(2001) Elizabeth B.-S. Sanders, Colin T. William, "Harnessing People’s Creativity: Ideation and Expression through Visual Communication", in Focus Groups: Supporting Effective Product Development, Langford J and McDonagh-Philip D, Taylor and Francis
(2004) P. Kristensson, A. Gusyafsson, T. Archer, "Harnessing the Creative Potential Among Users", in Journal of Product Innovation Management, 21.
(2008) Elizabeth B.-N. Sander, Pieter Jan Stappers, Co-creation and the New Landscape of Design, article in CoDesign, Taylor&Francis.
(2008) Nico MacDonald, Joe Haepy, Lynne Maher, Austin Williams, Can Good Design Be Co-created?, Design Council, paper.