Mats_Knutsson wrote:
The figure is basically for students that need to understand the whole concept in....5 minutes...

As an ArchiCAD teacher, I also use the "filter" concept, although I never went to the trouble of doing such a clear illustration.

The best I did was this:

I think you are on the right track, although I would try to give it some more visual appeal. If you manage to make a strong image out of it, students won't ever forget it, ergo the concept.