Since its inception in 2010, the Humanitarian OpenStreetMap Team (HOT) has coordinated thousands of volunteers in the creation of maps for humanitarian purposes. Contributors have traced satellite images and digitised field data in response to Typhoon Haiyan, the 2015 Nepal earthquake, the Ebola epidemic, and many other disasters. Despite these efforts, large parts of the world remain unmapped. With ambitions to fix this HOT are now trying to understand how to grow the largest crowdsourcing community on the planet.

Martin presents his research on this growth challenge. In attempting to understand how to recruit and retain an active contributor community, Martin’s research has covered the initial contributor experience, understanding the practices and concerns of the community and reviewing how expertise is shared. The research involves large-scale quantitative studies based on the contribution history of thousands of participants.