Building Web Reputation Systems

Chapter 10. Case Study: Yahoo! Answers Community Content Moderation

This chapter is a real-life case study applying many of the theories and practical advice presented in this book. The lessons learned on this project had a significant impact on our thinking about reputation systems, the power of social media moderation, and the need to publish these results in order to share our findings with the greater web application development community.

In the summer of 2007, Yahoo! tried to address some moderation challenges with one of its flagship community products: Yahoo! Answers. The service had fallen victim to its own success and drawn the attention of trolls and spammers in a big way. The Yahoo! Answers team was struggling to keep up with harmful, abusive content that flooded the service, most of which originated with a small number of bad actors on the site.

Ultimately, a clever (but simple) system that was rich in reputation provided the answer to these woes: it was designed to identify bad actors, indemnify honest contributors, and take the overwhelming load off of the customer care team. Here’s how that system came about.

What Is Yahoo! Answers?

Yahoo! Answers debuted in December of 2005 and almost immediately enjoyed massive popularity as a community driven website and a source of shared knowledge.

Yahoo! Answers provides a very simple interface to do, chiefly, two things: pose questions to a large community (potentially, any active, registered Yahoo! user—that’s roughly a half-billion ...