on alternative parametrisations in standard log-linear model

abstract: the issue of how to parametrise standard log-linear model has been neglected to some extent in the literature. in this paper general aspects of parametrisation are reviewed, in close connection with linear models theory. two main alternative parametrisations, which were exclusively used by different authors, are next discussed and compared with reference to theory of multiplicative interactions in contingency tables. finally, some aspects of implementation of different parametrisations are stressed with regard to estimation procedures and possible extensions of standard log-linear model.