If the events A and B are independent, what does that mean? Neither "There are no events in common" nor "The chance that A has occured is not changed by knowing that B has occured." There are no events in common between events A and B. The chance that A has occured is not changed by knowing that B has occured. Both "There are no events in common" and "The chance that A has occured is not changed by knowing that B has occured. ".