Sandra Barbosu, Joshua Gans, 30 November 2017

The design of the contribution mechanism for volunteers may affect the sustainability of crowdsourcing platforms. This column investigates how a change to the Zooniverse platform which meant that volunteers could no longer submit incomplete entries affected the number and quality of contributions. The results suggest that the total number of completed tasks by anonymous volunteers increased. The change in contribution design successfully encouraged them to channel their efforts into delivering fewer, higher-quality contributions, as intended.