An extension of model based partitioning for Bradley-Terry models is suggested by Strobl, Wickelmaier, and Zeileis (2009). An application to mixed models, including the Rasch Model as a special case (as a generalized linear mixed model, see Rijmen, Tuerlinckx, Boeck, and Kuppens 2003; Doran, Bates, Bliese, and Dowling 2007), is currently investigated by Sanchez-Espigares and Marco (2008).