In the United States and Canada, it now generally refers to the process by which prospective jurors are questioned about their backgrounds and potential biases before being chosen to sit on a jury. It also refers to the process by which expert witnesses are questioned about their backgrounds and qualifications before being allowed to present their opinion testimony in court. As defined by Gordon P. Cleary: "Voir Dire is the process by which attorneys select, or perhaps more appropriately reject, certain jurors to hear a case."[4] As noted above, in the United States (especially in practice under the Federal Rules of Evidence), voir dire can also refer to examination of the background of a witness to assess their qualification or fitness to give testimony on a given subject.[5]