leukemia "recalls" coffee consumption during pregnancy differently from a mother whose

child does not have leukemia. You would want to know that at the time of the face-to-face

interviews that the parents responding were not aware of the study hypothesis because

that could influence how mothers reported their coffee consumption during pregnancy. If

they thought the investigators suspected that coffee consumption increase the risk of

leukemia, the mothers whose children were diagnosed with leukemia might report less (or

more) coffee consumption than actually occurred. This could be done by embedding the

coffee questions in a general survey about eating and exercise habits during pregnancy.