Co-design is a philosophy in the American pragmatist tradition, which argues that all people have different ideals and perspectives and that any design process needs to deal with this. Co-Design traces its roots to Emmanuel Kant, who in the Critique of the Pure Reason observed that to put a question one has to have some information or knowledge. Kant called this a priori knowledge. Therefore the concept of objectivity is regarded to be difficult or even meaningless. William James suggested that the criteria for truth should be "useful", which is a cornerstone in Co-Design thinking.

In co-design there is an understanding that all human artifacts are designed and with a purpose. In co-design one tries to include those perspectives that are related to the design in the process. It is generally recognized that the quality of design increases if the stakeholders interests are considered in the design process. Co-design is a development of systems thinking, which according to C. West Churchman "begins when first you view the world through the eyes of another."

People who have contributed in the field are:

• William James
• Edgar A. Singer
• C. West Churchman
• Russell L. Ackoff
• Donald Schön
• Olov Forsgren
• Lars Albinsson

Co-design is applied in many fields, for instance architecture, information systems and business. It has recently become popular in mobile phone development, where the two perspectives of hardware and software design are brought into a co-design process C.f. .

Co-design is different from for example participatory design in that it does not assume that any stakeholder a priori is more important than any other. It also differs from various user-centered design approaches in that it acknowledges that the client or beneficiary of the design may not be using the artifact itself.

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