Public participation in scientific research (citizen science or CitSci) engages diverse people and stakeholders in science through collaborative and transformative initiatives. The NREL offers a wide array of support services for citizen science endeavors – from its renowned global citizen science support platform CitSci.org to hands-on engagement of our staff in projects spanning bioblitz events at National Parks to large-scale crowdsourcing of algae bloom monitoring in high alpine lakes to development of customized portals and mobile applications for citizen science. The Lab also studies the effectiveness of citizen science endeavors and factors affecting the collective impacts and outcomes of citizen science for science, society, and socio-ecological systems.