Why did the British Army test radar gunsights under real operating conditions?

The British Army tested radar gunsights under real operating conditions because traditional methods of testing equipment were found to be ineffective for this new technology.1

Initially, the British Army struggled to use radar effectively to control the fire of antiaircraft weapons. Because the standard testing protocols did not apply to these radar systems, scientists—led by the physicist P.M.S. Blackett—determined that it was necessary to conduct field tests under actual operating conditions to solve the antiaircraft problem.1

This effort was a foundational development in operations research, as it moved beyond analyzing physical equipment to examining the behavior of operating personnel and the limitations of the communication networks. By studying the systems in the field, researchers were able to identify ways to improve operator techniques and address previously unappreciated limitations in the military's defensive network.1