Filipinos come to Hong Kong because they need money, but they stay because they feel happy. If they don't feel happy they won't stay. Their job satisfaction is related to the feedback you give them. If you don't give them feedback they will assume that they are not doing a good job and that you don't like them. If you give them feedback even if it is partially corrective they will appreciate it because they know they are accepted and doing an ok job. If you give them some positive feedback they will go "off The Charts" happy and send me a message like the one you see below.
You can find some guidelines on how to do a performance review here: http://arrowes.hk/more/. At Arrow our goal is to help you find and KEEP a good helper.