A quick post I wrote for the Viget UX blog on five major identity schemes, how they’re used effectively, and how to go about working out a scheme for your product:

The key to choosing a system is balancing the needs for the contributor’s privacy against the skepticism of the consumers. In Yelp’s case, a pseudonymous identity system might lead some to think that many reviews of local restaurants are being posted by the restaurant staff itself. That might still be the case, but at least it’s discouraged by the emphasis on abstracted real names. In Facebook’s case, privacy in terms of identity isn’t really necessary for people who are supposed to know each other anyway. For a forum dealing with sensitive topics like disgruntled workers, relationships, or medical issues, anonymity might be crucial to creating a safe haven for people to share their thoughts.

It’s easy to overlook, and can be tough to change later…