“…Since multivariate normality plays a central role in all these approaches, one must, however, remain alert to the impact on the results of possible departures from multivariate normality [Hopper, 19861. Fortunately, if actual data are highly non-normal, it is possible to enhance normality by means of suitable (marginal) data transformations [eg, Andrews et al, 1971Andrews et al, , 1973Rao et al, 1984b;McGue et al, 19871. This may be accomplished by assuming that a certain transformation of X, and not X itself, is multivariate normally distributed [eg, MacLean et al, 1976;George and Elston, 19871.…”