Fun

The user considers the act of contributing a fun thing to do, and it motivates him to doing it.

eBird

eBird is a birding community that reports and accesses information about birds. Launched in 2002 by the Cornell Lab of Ornithology and National Audubon Society, eBird provides rich data sources for […]

Galaxy Zoo

To understand how galaxies have formed, astronomers need your help to classify them according to their shapes. If you’re quick, you may even be the first person to see the […]