1. SUMMARY (1) An account is given of a factor analysis of the mortality experience of males in England and Wales during 1950-1953, using the method of principal components
2. For several causes-of-death, an important determinant of the level of recorded mortality is a factor which appears to represent diagnostic precision
3. About half the age-adjusted variance as between administrative areas for five causes-ofdeath (malignant disease of stomach, of lung, and of Abbatt;D., J.;Lancet,1957
4. Acheson, R. M. (1960). Brit. J. prev. soc. Med., 14, 139.
5. Buckatzsch, J., and Doll, R. (1952). J. Hyg., 50, 384.