Participatory UX

How do you design a user experience that does something beyond compelling a user to take a specific action, to change their perception of what is possible and to inspire them to use their talent collaboratively to take actions that can lead to real positive change?

How do you design technology systems that encourage and reward participation by enabling collaboration that values individuals and works at the scale of a technology platform?

Imagine a platform like Wikipedia, redesigned with a focus on enabling and encouraging collaborative contribution. What can be learned from the massive resources that have been dedicated to engage users in platforms that serve the goals of marketers (Facebook, Google) and how might that be applied to build platforms that serve the goals of humanity?