Primo Levi and Louis Malle's work

Primo Levi and Louis Malle's work How would Levi and Malle define the personal and the historical meanings of bearing witness? Be sure to discuss both the method and the purpose of witnessing. Sources: Primo Levi's The drowned and the saved Survival in Auschwitz Louis Malle's Movie; Au Revoir Les Enfants (can be watched on hulu)