description

Confirmation Bias is the tendancy to seek out evidence that is consistent with an hypothesis, instead of seeking out evidence that could disprove it.

Popperian philosophy proposes that objective knowledge must be disconfirmable, and so much of science is based on experimental designs intended to disprove the hypothesis, instead of confirm it.

examples

Very common in testimonials. Purveyors of quack remedies only rarely seek out people for whom the treatment didn't work, but concentrate their interest on those who believe they have been cured.

There are these enthusiasts who build fliers (light electronic constructions that float in the air when an electrical charge is applied) and they spend quite some time repeating these flights, which they argue work by defeating gravity. The way to disprove the hypothesis is to fly the devices in a vacuum, to see if instead the effect is caused by mundane ion wind. They don't do these experiments, preferring instead to endlessly repeat the confirmatory flights.