The information systems of public institutions play a crucial role in how we collectively look at and act in the world. They shape the way decisions are made, progress is evaluated, resources are allocated, issues are agged, debates are framed and action is taken. As a United Nations (UN) report recently put it, “Data are the lifeblood of decision-making and the raw material for accountability.” Every information system renders certain aspects of the world visible and lets others recede into the background. Datasets highlight some things and not others. They make the world comprehensible and navigable in their own way – whether for the purposes of policy evaluation, public service delivery, administration or governance. Given the critical role of public information systems, what happens when they leave out parts of the picture that civil society groups consider vital? What can civil society actors do to shape or in uence these systems so they can be used to advance progress around social, democratic and environmental issues? This report looks at how citizens and civil society groups can generate data as a means to in uence institutional data collection. In the following pages, we pro le citizen-generated and civil society data projects and how they have been used as advocacy instruments to change institutional data collection – including looking at the strategies, methods, technologies and resources that have been mobilised to this end. We conclude with a series of recommendations for civil society groups, public institutions, policy-makers and funders.