During World War I, the need to break the deadlock of trench warfare saw the rapid development of many new technologies, particularly tanks. Military aviation was extensively used, and bombers became decisive in many battles of World War II, which marked the most frantic period of weapons development in history. Many new designs, and concepts were used in combat, and all existing technologies of warfare were improved between 1939 and 1945.
Leading war poets included Siegfried Sassoon, Wilfred Owen, John McCrae, Rupert Brooke, Isaac Rosenberg, and David Jones. A similar movement occurred in literature, producing a slew of novels on both sides of the Atlantic, including notably: All Quiet on the Western Front, and Johnny Got His Gun. The 1963 English stage musical Oh, What a Lovely War! provided a satirical take on World War I, which was released in a cinematic version directed by Richard Attenborough in 1969.
After the final ability estimate is computed, it is converted to a standard score on the ASVAB score scale that has been statistically linked to the ability estimate through a process called equating. Equating studies are conducted for every paper and pencil ASVAB form to ensure that scores have the same meaning regardless of which test form the examinee receives.