We have been able to develop a really nice module for Moodle elearning classes which will helps in tracking the progress of a online class in a graphical dashboard format. more than words to explai what it does, you can have a look at the demo of it at www.sitact.net.
It is good to develop tools for quick analysis of student performance. I would like to see different data being used. Something that analyses student use of moodle, within a particular course (my course set as a teacher) in a similar graphical snapshot format.
The data you have used shows comparative performance of students in a class but the input required to set this data up is not clear. This is the element that needs a lot of work to make it a simple and straightforward process to collate and compare student progress. I find the data you have input unclear and therefore hard to relate to my classroom situation.
I would look at this tool if it promised me something I would find quickly accessible and useful. It looks good but I don't see the substance because data is not relevant and I don't know how I would set it up for myself.