Title: The Impact of Optional Game Mechanics and Email Notifications on Player Contributions and Return Rate in Mozak
Advisors: Zoran Popović and Katharina Reinecke
Abstract: We describe the effect of optional tutorial components and email notifications on the retention rate and useful contributions of players in the neuroscience crowd-sourcing game Mozak. We performed between-subject experiments with data collected from 7,000 online players and 1400 registered players, and measured time played, amount of scientific contributions made, and return rate. We found that framing mandatory tutorials as optional game mechanics had positive effects on overall player contribution and return rate, but may decrease time played for new players. Email notifications was found to increase return rate, but not player contributions. Our results suggest that framing tutorials and optional game mechanics can be highly beneficial for online crowd-sourcing games. In addition, our work indicates that single-session play-time is not a reliable metric for evaluating player engagement, as it did not strongly correlate with other metrics previously attributed to player engagement.