Matthew Baerman is Senior Research Fellow in the Surrey Morphology Group at the University of Surrey, whose work concentrates on the description, typology and diachrony of morphology, particularly complex infllectional systems. He is the editor of the recent Oxford Handbook of Inflection (2015). Dunstan Brown is Professor and Head of the Department of Language and Linguistic Science, University of York and a Visiting Professor in the Surrey Morphology Group. Recent publications include: Network Morphology (with Andrew Hippisley, 2012); and as co-editor, Canonical Morphology and Syntax (2012), Understanding and Measuring Morphological Complexity (2015) and Archi: Complexities of Agreement in Cross-Theoretical Perspective (2016). Greville G. Corbett is Distinguished Professor of Linguistics, University of Surrey, where he leads the Surrey Morphology Group. He works on the typology of features, as in the previously published Gender (Cambridge, 1991), Number (Cambridge, 2000), Agreement (Cambridge, 2006) and Features (Cambridge, 2012). He is a Fellow of the British Academy and of the Academy of Social Sciences, a Member of the Academia Europaea and an Honorary Member of the Linguistic Society of America.