In my field, recreational therapy, we teach students to use "People First" terminology. This means, no matter what the adjective is, the person is the focus. Hence, instead of saying "a half black kid", we should say a child that is multi-racial/bi-racial/whatever. I seriously doubt that there was half a child in your class, and although I'm using this in quite the literal sense, I'm trying to express how condescending people can "sound" when speaking/typing/talking/whatever.