Which of the following types of bias can be reduced by allowing equal interview time?

Interviewer bias can be kept under a useful check by making note of the time length taken to interview the average case and also the average control. This type of information bias usually occurs when the interviewer elicits inaccurate information from study subjects either consciously or unconsciously. Ref: Park's Textbook of Preventive and Social Medicine By K. Park, 19th Edition, Pages 68, 69, 78; Encyclopedia of Epidemiologic Methods By Mitchell H. Gail, Jacques Benichou, Page 455