NACA expanded its pool of women human computers in the 1940s. NACA recognized in 1942 that "the engineers admit themselves that the girl computers do the work more rapidly and accurately than they could." In 1943 two groups, segregated by race, worked on the east and west side of Langley Air Force Base. The black women were the West Area Computers. Unlike their white counterparts, the black women were asked by NACA to re-do college courses they had already passed and many never received promotions.