Here you can have an overview of the charts atm supported, i have lots of things to do but i'm implementing new charts (on quizzes, assignments, forum rates, ...) i only need more then 24 hour on each day ;)
http://www.istituti.usilu.net/milanic/web/GISMO.html
Lots of idea on my mind... and not so much time to realy implement them
Remember that i choosed java for the interactivity with the user (mouse events, keyboard events). You can right click on every 'point'/'bar histogram'/'student list'/'group list'/'resource list' and you have some options (select,deselect, details, ...)
The idea is: I show you everything, and the user choose what he wanna see! No algorithms, human brain!
Surely someone of you will say: "it gives only more questions and not answers".
I can say NO, you need to know who's behind the username... all these visualisations can help, but they aren't standalone. If someone want to speak about this problem, i don't think this is the right place.
CYA!!!