Models for asymmetric proximities

All major models for asymmetric proximities are a combination of a symmetric similarity component and an asymmetric dominance component. The differences and similarities between the methods that are discussed in this paper are revealed by applying a certain decomposition to the model parameters, clearly separating the dominance and symmetric similarity component. The notion of skew-symmetry turns out to be an often seen element in modelling asymmetry, although sometimes in disguise and difficult to recognize. The decomposition shows that there are two classes of models, one that assumes that the asymmetric relationships are transitive, while the other class consists of models that can also represent circular asymmetric relationships.