Ruth Stewart (pictured) is professor of evidence at the University of Johannesburg. She has a background in social sciences, and has worked across academia and government. Stewart founded and chairs the Africa Evidence Network, the world's first and largest cross-sector regional evidence network. She also founded and leads the Africa Centre for Evidence at the University of Johannesburg. Carina von Rooyen is a senior researcher at the Africa Centre for Evidence, where she co-directs the South African Centre of the Collaboration for Environmental Evidence.