In this piece from the Items archive, Carl I. Hovland, Arthur A. Lumsdaine, and Fred D. Sheffield encapsulate the work of volume III of The American Soldier series, Experiments on Mass Communication, which analyzed efforts at indoctrination and instruction conducted on soldiers during World War II. In particular, they highlight the controlled experiment comparisons on responses to the US Army’s “Why We Fight” film series, as well as the limitations of conducting research on the effectiveness of various media of communication.