You can change the permission level for users you've shared your calendar with (see Personal Calendar or Shared Team Calendar for how to share a calendar). For more information on permission levels refer here.
Set permissions in OWA (web-app)
- Login to your email at email.scu.edu.au
- Select 'Calendars' from the top of the screen
- Right click on the calendar you would like to share and select permissions
- In the new window that opens, find the member that you have shared the calendar with, and adjust their permissions using the dropdown box.
After making the changes, select save from the top of the window to save the changes.