The role system, with its four types of permission (allow/inherit/prevent/prohibit) is very difficult to understand and can cause serious confusion, mostly with people choosing 'prevent' or 'prohibit' when they shouldn't. In most cases you only ever need to choose 'Allow', or leave it at 'Inherit'. The other two are needed for rarer special cases.
I suggest that there should be a basic view for the 'define role' screen which shows checkboxes instead of the radio buttons as follows:
- If the capability is set to 'Allow', it shows a ticked checkbox
- If the capability is set to 'Inherit', it shows an unticked checkbox
- If the capability is set to something else, it shows the word 'Prevent' or 'Prohibit', with no option to change (unless you switch into advanced mode).
When you switch into advanced mode it displays as now.
This would make the role interface significantly easier to understand.
(Note that the OU may possibly have time to implement this. If moodle hq would like us to, please let me know.)