Starting with version 8.1, you may now designate how many interpreters are required to be assigned to a job.  To do so, you select the number in the control above the 'Assigned Interpreters' box on the Interpreters tab of a request. 

What this affects is that a job will continue to show as 'Unassigned' while the number of Assigned Interpreters is less than the 'Number of Interpreters Required'.  This affects not only the 'Unassigned' tab of the Dashboard, but also the calendar view.  Requests in the Calendar will remain Red until this condition is met as well.  Same for all cases throughout Atrium where this Unassigned property is used.