Citizen inquiry involves members of the public in devising and running mass-participation investigations. The aim of citizen inquiry is to combine the creative knowledge building of inquiry-based learning, the excitement of scientific discovery and the mass civic engagement of volunteer activism. Citizen inquiry could be developed as extensions of current citizen science projects, offering additional opportunities for individuals and groups to devise new investigations, guiding people through the process of creating and running a study. Citizen science involves thousands of people in collecting data or solving problems to assist scientists in their investigations. Zooniverse and nQuire are two sites for people, schools or communities to manage citizen inquiry projects. Citizen inquiry turns this relationship around — citizens devise the investigations and scientists offer assistance. Creating an online community for citizen inquiry requires difficult design decisions.