The following post is derived from a precis I wrote in Foundations of HCI over a year ago.
In the paper "Why Users of Yahoo! Answers Do Not Answer Questions", Dearman and Truong present a few suggestions for improving Yahoo! Answers (YA) question and answer process and interface to maximize user participation in giving quality answers to questions. After conducting a 15-week experiment, Dearman and Truong found that: 1) YA’s top and regular contributors do not answer questions for the same basic reasons (see bullet points below). 2) This problem could be solved by a few research and design approaches.