Bess et al. <1992> have stated that empirical orthogonal functions computed from spherical harmonics amplitudes and transformed into grid point space are identical to empirical orthogonal functions (EOF) of grid point data derived from the transformed amplitudes if and only if an equal area grid is used. It will be shown that this does not hold in general and that there is always a one-to-one correspondence between EOF's in spherical harmonics or grid point representation. The equal area grid is only a special case of a more general approach. A simple example is given to illustrate the results of the mathematics. ¿ American Geophysical Union 1993