Discussion on the paper by Handcock, Raftery and Tantrum by Snijders, T, Robinson, T, Atkinson, A, Riani, M, Gormley, I, Murphy, T, Sweeting, T, Leslie, D, Longford, N, Kent, J, Lawrance, T, Airoldi, E, Besag, J, Blei, D, Fienberg, SE, Breiger, R, Butts, C, Doreian, P, Batagelj, V, Ferligoj, A, Draper, D, van Duijn, MAJ, Faust, K, Petrescu-Prahova, M, Forster, J