Undeceivers

Confirmation bias means that information is searched for, interpreted, and remembered in such a way that it systematically impedes the possibility that the hypothesis could be rejected.

Example #1

You and your friend passionately disagree on whether milk is healthy or not. You both turn to the internet to find out who's right. After doing your research your friend has found 5 sources that support their initial standpoint and you have found 5 sources that support yours, one of which is the same source! You both ignored or skimmed over sources, judged sources more critically when they did not agree with you, and interpreted sources differently informed by your preconceptions.

Example #2

Every time you wear your red shirt something bad happens to you. One day you have nothing else to wear, you put your red shirt on, and at the end of the day you happen to stub your toe, proving once again that red shirts are imbued with an evil magic. You've conveniently forgotten the numerous times that bad things happened when you were wearing other shirt colours or the times when you wore a red shirt without anything bad happening.

Sources

Oswald, M. E., and S. Grosjean, Confirmation bias. In R. F. Pohl (Ed.). Cognitive Illusions. A Handbook on Fallacies and Biases in Thinking, Judgement and Memory, (Hove and N.Y.: Psychology Press, 2004)

Plous, S., The Psychology of Judgment and Decision Making, p. 233 (New York, NY, USA: Mcgraw-Hill Book Company, 1993)