There was a presentation on ICSE 2011, at the New Ideas and Emerging Results track, entitled ["How do programmers ask and answer questions on the web?"](http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6032523&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D6032523). They only had initial results, but they sounded very interesting and promising. Maybe you could contact the authors if you need more info (they're from the Dept. of Comput. Science, University of Victoria, Victoria, BC, Canada). Here is the full reference:

Treude, C.; Barzilay, O.; Storey, M. **How do programmers ask and answer questions on the web?**. In Proc. of the 33rd International Conference on Software Engineering (ICSE), 2011.