The Making Sense project (2015-2017) explored how local communities can effectively use open-source software and hardware, digital maker practices and open design to produce their own sensors. In the pilot UrbanAirQ in Amsterdam, citizen scientists decided what they wanted to measure and why. In this case, they chose NO₂ as an indicator of air quality. The participants raised diverse questions and concerns about air pollution which helped design the approach of the pilot itself. 74 Visit the project website