Types Biased search for information thumb|right|200px|alt=A drawing of a man sitting on a stool at a writing desk|Confirmation bias has been described as an internal "yes man", echoing back a person's beliefs like Charles Dickens's character Uriah Heep. Experiments have found repeatedly that people tend to test hypotheses in a one-sided way, by searching for evidence consistent with their current hypothesis. Rather than searching through all the relevant evidence, they phrase questions to receive an affirmative answer that supports their theory. They look for the consequences that they would expect if their hypothesis was true, rather than what would happen if it was false. For example, someone using yes/no questions to find a number they suspect to be the number 3 might ask, "Is it an odd number?" People prefer this type of question, called a "positive test", even when a negative test such as "Is it an even number?" would yield exactly the same information. However, this does not mean that people seek tests that guarantee a positive answer. In studies where subjects could select either such pseudo-tests or genuinely diagnostic ones, they favored the genuinely diagnostic.
Types Biased search for information thumb|right|200px|alt=A drawing of a man sitting on a stool at a writing desk|Confirmation bias has been described as an internal "yes man", echoing back a person's beliefs like Charles Dickens's character Uriah Heep. Experiments have found repeatedly that people tend to test hypotheses in a one-sided way, by searching for evidence consistent with their current hypothesis. Rather than searching through all the relevant evidence, they phrase questions to receive an affirmative answer that supports their theory They look for the consequences that they would expect if their hypothesis was true, rather than what would happen if it was false. For example, someone using yes/no questions to find a number they suspect to be the number 3 might ask, "Is it an odd number?" People prefer this type of question, called a "positive test", even when a negative test such as "Is it an even number?" would yield exactly the same information. However, this does not mean that people seek tests that guarantee a positive answer. In studies where subjects could select either such pseudo-tests or genuinely diagnostic ones they favored the genuinely diagnostic.