You can stop reading right there. Tests cannot be biased, although the teacher can. Test bias is a complete oxymoron. The student either knows the material or they do not.
It is possible for the grader to be biased on certain types of tests (essay tests, for instance) but in a multiple choice or fill-in-the-blank test, as standardized tests typically are, bias is impossible. The student either knows the material or they do not. If they do not, they fail. If they do, they pass. It's pretty simple.
Ah, you obviously do not understand the need for empathy for the student that was:
not loved enough.
loved too much.
poor.
born to immigrant parents.
in a divorced family.
other:__________________________________
PICK ONE! /sarc