5. Lessons learned
Visual quality control is a feasible application of crowdsourcing. We operate under the assumption that participants in scientific experiments, such as the optical imaging survey DES, are genuinely interested in data flaws relevant to their science cases. Indeed,we found – and have been told – that if the interaction with the application is streamlined and frustration-free, our users enjoyed exploring the data, either to inspect the quality of new releases or, for new participants, to get to know their current state. Many users suggested improvements to the applications (e.g. the fieldof-view visualization) that extended its capabilities and made the exploration more efficient and illuminating. We also found that users can be further motivated by newsletters, gaming incentives, such as badges and leaderboards, and follow-up investigations of unexpected discoveries. These findings all point to an engaged user base, and our usage statistics support such an interpretation.