changing default screen options for Posting editor

I have several authors and all members can contribute to my site. Many, if not most, contributors are not familiar with the interface and how to set preferences, so I have to do it for them. The default screen options for the posting editor do not seem to include the ‘Discussion’ box selected. Is there a way to change the default for all users to have certain screen options selected? Any help on this would be appreciated.

zuimoon.com