CITIZEN SCIENCE: THEORY AND PRACTICE Special Collection: Impact Assessment and Evaluation CITIZEN SCIENCE: THEORY AND PRACTICE Call for Abstracts Issue editors: Stephen Parkinson1,2, Luigi Ceccaroni1, Maina Muniafu3, James Sprinks1, Uta Wehn4,5 Earthwatch Europe, Oxford, UK University of Nottingham, UK USIU-Africa, Nairobi, Kenya IHE Delft Institute for Water Education, Netherlands CWTS Leiden University, Netherlands Citizen Science: Theory and Practice is an open-access, peer-reviewed journal providing a central space for cross-disciplinary, scholarly exchanges aimed at advancing the field of citizen science by providing a venue for citizen science researchers and practitioners to share best practices in conceiving, developing, implementing, evaluating, and sustaining…