In 大學既 RA post

i think it's almost the same as outside jobs...
they look at how suitable u are for their job...based on ur education background/knowledge, ur personality, ur passion for the job etc...and of course largely based on ur impression to them...how well u present urself to them that u want the job~  

i think that if the intervierwer is chinese they would probably have the conversation in chinese~
but i guess u'll find out if they will "switch channel" once they start speaking in english instead~