ABSTRACT
The trouble was that none of the tests based on the cues for depth predicted the success or failure of a student pilot, and none of the proposals for improving depth perception by training made it any easier to learn to fly. I was deeply puzzled by this fact. The accepted theory of depth perception did not work. It did not apply to problems where one might expect it to apply. I began to suspect that the traditional list of cues for depth was inadequate. And in the end I came to believe that the whole theory of depth perception was false.
