Harper, F.M., Xin Li, S., Chen, Y. & Konstan, J.A. (2007). [Social comparisons to motivate contributions to an online community](http://www.springerlink.com/index/43m3303081659655.pdf). Persuasive Technology. pp. 148-159.

on designing software to encourage contribution:

>...designers of Web sites can hope to affect the volume of user contributions through design. They might take action to change the costs of the contribution by making contributions easier to make.

on providing comparisons of levels of contribution, compared to peers:

>Online communities wishing to promote contributions of a certain kind may wish to display information that leads members to evaluate their level of contribution. While many Web sites display information about superstar users (such as with Amazon's "Top Reviewers" list), it is also possible to compare users with their peers in the system. In this way, users may be motivated by the presence of more attainable goals.

*how would the "members" page on a WP class blog site fit with this model of peer comparison? is there something similar in Bb?*