Birkelo, C.C. , et al., 1947. Tuberculosis case finding. J. Amer. Med. Assoc., 133, p. 359. See also "Observer Error," Lancet, Jan. 9, 1954 , P. 87.
2.
A useful introduction to this work is given by W.H. Ittelson and F.P. Kilpatrick, Experiments in Perception, Scientific American Reader, 1953, New York, Simon & Schuster. See also M.L. Johnson, Seeing's Believing, 1953, New Biology15, Harmondsworth, Penguin Books.
3.
Davis, D.R., and Sinha, D.1950. The effect of one experience upon the recall of another . Q. J. Exper. Psychol., 2, 43-52.
