A type of information bias that is of importance in case-control studies. It means that cases differ from controls in the recollection of exposure.
Distortion introduced into a research investigation that relies on the memory of subjects, specifically, their recollections of elements that might have contributed to the eventual development of a disease or condition. A research subject’s memories after the occurrence of an adverse event, e.g., the diagnosis of a serious ailment, may be unduly influenced by his or her assumptions, beliefs, expectations, or prior education about possible causes of that ailment and thus may not reflect the true breadth of exposure contributing to the occurrence of the disease.