Ahistorian interviews two people who fought during a certain battle during the gulf war. one person says u. s. forces fired first, the other person says iraqi forces fired first. to try to learn what really happened, the historian should

They should interview other people who fought in that same war ( which would be back up witness for these two different accounts). So whoever has the most back up witnesses must be telling the truth ( also make sure the other people you interview don't know they are back up witness).