at the moment, for what i know,qatar is inteviewing only DEC or SFI.
PAT test is a 3.5 hours including interview,test,debrief.
you are required to perform an online test before you arrive in Doha and to read the book they send you few days before .
it is not a pass /fail test ..they want to know you and your behaviour and ,if i can suggest, try to be as much honest as you can to have the best result
i found the whole process very accurate ...it is not the usual chat with some psyco or group test..
you cannot prepare yourself for that but readind the book they send you.
