In English | En español
Questions About Cancer? 1-800-4-CANCER

NCI Dictionary of Cancer Terms

Page Options

  • Print This Page

Widget

NCI Dictionary of Cancer Terms



selection bias  listen  (seh-LEK-shun BY-us)

  An error in choosing the individuals or groups to take part in a study. Ideally, the subjects in a study should be very similar to one another and to the larger population from which they are drawn (for example, all individuals with the same disease or condition). If there are important differences, the results of the study may not be valid.