Justin Ward, Warwick Maximising Bisubmodular and k-Submodular Functions Submodular functions play a key role in combinatorial optimisation and in the theory of valued constraint satisfaction problems. Recently, there has been interest in various generalisations of submodularity, including bisubmodular functions, which operate on disjoint pairs of sets, rather than single sets. Like submodular functions, bisubmodular functions can be minimised exactly in polynomial time and exhibit the property of diminishing returns. In this talk, I will present recent joint work with Stanislav Zivny on maximising both bisubmodular functions and also general k-submodular functions, which operate on disjoint k-tuples of sets. Additionally, I will discuss the relationship between bisubmodularity and submodularity, and show how our results on bisubmodular functions can provide intuition for existing algorithms that maximise submodular functions, such as the recent 1/2-approximation algorithm of Buchbinder, Feldman, Naor, and Schwarz.