A mistake made in reasoning in which a judgment is made that depends excessively on preconceptions, bias, or an initial point of reference. For example, a patient on a hospital neurology service is found unconscious. Her caregivers assume (are committed or anchored to the idea) that, like many other patients cared for on the neurology service, she may have suffered a stroke. She is sent for an imaging study of the brain to rule out stroke. Other common and potentially deadly causes of coma, e.g., a dangerously low blood glucose level, are overlooked during her initial assessment.