<prompt> Which of the following is true regarding random error:Systematic differences in characteristic between cases and controlCases and controls are asked questions about their past historyError in samplingDifferent rates of admission in hospital  <response>: sampling error Berkesonian bias is a special example of bias. It is named after Dr. Joseph Berkson who recognized this problem. The bias arises because of the different rates of admission to hospitals for people with different diseases hospital cases and controls. Recal bias: differential recall ability between the cases and the controls Neyman bias: differential moality between groups, which is not accounted for. 