Policies are stored in the file called ABControl.xml (v7) or ABTutor.xml (v8). This file is located in the following places:
|Mac OS||/etc/abtutor/Tutor /Users/$user/Library/Preferences/abtutor/Tutor|
You will need to make sure that teachers have access rights to write/modify this file.
If you have chosen to share a single ABControl.xml with all your AB Tutor machines over the network, you will need to make sure that your teachers have access to the network location at which you have stored the file. - See Related Question "Do we need to recreate a set of policies for each tutor workstation."