Tertiary work is a historian's synthesis built from primary and secondary material. A sailor in a ship's engine room and someone in the gun director experience the same battle from different positions, which shapes what each observes and concludes. Neither perspective alone can reconstruct the engagement. Historians compare as many accounts as possible and set them in context to build a fuller picture of what happened. Source grades identify how close the evidence is to the event, while corroboration shows how separate accounts fit together.
Notable Point · 1:40-2:51
Reconstructing a battle from different viewpoints
A historian's synthesis grows from comparing partial firsthand perspectives, such as those of an engine-room sailor and a gun-director crew during the same battle.