bias

Bias can have two meanings.

The first meaning of bias is favoring a person or thing over others because of personal feelings, not because of objective and fair judgment.

For example:

Companies whose top jobs go only to men show a bias against women.

I have a bias for sweet desserts: I never touch the healthy ones.

In a research context, a biased sample describes a sample that is not representative. For more on this meaning of biased, select AWL word 'random' and see Exercise 4.