The International Workshop on Statistical Modelling is an annual conference organised by the Statistical Modelling Society. The workshop concentrates on the various aspects of statistical modelling, including theoretical developments, applications and computational methods. Papers motivated by real practical problems are encouraged, but theoretical contributions addressing problems of practical importance or related to software developments are also welcome. See http://www.statmod.org for more about the history and philosophy of the workshops. The 20th IWSM will be the first to be held in the southern hemisphere.