Review of “Ethnic Variables in Human Factors Engineering. Edited ” by Alphonse ChApanis-(Baltimore: Johns Hopkins University Press, 1975.) [Pp. xviii + 290.] £9-50.

Measurements were made of the motion of a ship, and of the consequent seasickness experienced by passengers. Data are presented for 17 voyages of up to 6?hours duration, involving 4915 passengers. Vertical motion occurred up to 1·0 m s^?2 r.m.s. and vomiting incidence of up to nearly 40% was encountered.

Both vomiting incidence and illness rating correlated well with root mean square vertical z-axis acceleration. The effect of exposure duration was also investigated, producing suggestions for a combined measure of acceleration and time. Multiple regression analysis with all six axes of motion revealed only a small increase in correlation when all directions of motion in addition to the z-axis were taken into account.