The modularity of a ribbon Hopf algebra is characterized by the Drinfeld map. An elementary approach to Etingof and Gelaki's (1998, Math. Res. Lett. 5, 119-197) result on the dimensions of irreducible modules is given by deducing the necessary identities involving the matrix (S-ij) from the well-known orthogonal relations of Hopf algebra characters. (C) 2001 Academic Press.