Here is a list of questions that people researching the effectiveness of virtual worlds would like to be able to collect data about.
Where's the activity?
Number of users over a certain period of time
Number of simultaneous users over time
Heat maps showing accurate traffic data
Record of applications used and for how long
Who's collaborating?
Avatar locations and proximity to other avatars
Number of people in "ear shot" of a talking avatar
Number of times control passes in shared applications
Number of avatars in proximity to an application being shared
What happened?
Record of which interactive objects or applications were used
Automated video recordings of certain spaces
Record events to play back later and view from different perspectives