Opinion or pro & con articles, books, or other resources with bias are ideal to use in argumentative papers or presentations. They can also be used for informative research assignments, but you have to be more careful so as not to produce an unintentionally biased paper or presentation that is meant to be objective.
Biased means unfairly prejudiced or someone's opinion altering their answers, which is bad because the answers they give you are most likely false or too opinionated.
