I'm carrying out some research on Stack Overflow. As part of the research I want to develop an app that visualizes change in SO over time. However I need to establish useful and meaningful metrics. The premise here is that metrics suggested by an external analyst are less meaningful than metrics devised by the community. It is based on the idea of being inside or outside a system. What is considered meaningful is different for those inside the system than for those outside. The tool I want to build is for the community and not for a social scientist or internet researcher.
So, with this in mind, has anyone any tentative suggestions on measuring SO? Things they would perceive as useful, correlations etc. I hope to base any measurement on a temporal scale so there is the possibility of establishing points of change.
P.S.: Here is an interesting post about devising metrics and community algorithms for the blogosphere. If I need to put this in StackApps, please let me know.