Recently active topics in PBwiki tagged with teacher

I have a "Gold" wiki and am confused about how the different types of users work. I am a teacher in an elementary school and want to use it in the following ways:
1) Students can edit.
2) I will be notified when students edit and it will tell me who edited.
3) Nobody else can edit, but they can read.

I thought by adding users and setting them up as contributors or readers, this is how it would work. But I just received an email notification that someone "unknown" had edited the page. Based on the information edited, I knew which student it was, however, it didn't say his name. It just said "unknown". That makes me wonder if anyone can edit it. If so, have I set it up incorrectly?

I am a new participant and i wish to keep my students' emails addrresses private or hidden. Is there a way for my students to edit wiki pages so that I know who has worked, but so their email addrresses are hidden from view of everyone but me?