In 2015 we set up a volunteer project to map roads & villages in rural Tanzania, focusing on fighting female genital mutilation (FGM) in the Serengeti district. One year later, Crowd2Map volunteers have mapped >42K km of roads, >700K buildings, and identified hundreds of villages. Some of these were done in real time during the cutting season, to urgently find & reach specific reported FGM cases. Most importantly, the Mugumu Safe House saved 2257 girls this year; 1076 girls were still cut, down from 3700 girls last year.

We see FGM as a solvable problem in which maps can have significant impact. On the other hand, measuring impact on such complex issues in developing countries is not an easy task.

In this talk we are going to present our methods for collecting qualitative and quantitative data for measuring the impact of maps in Tanzania, working in direct contact with communities, local officials and government data, and discuss their limitations. Our approach could be adapted to other countries and problems where the impact of maps often seems “obvious”, yet is poorly researched.