This thesis describes three families of tools for exploring data and models. It is organised in roughly the same way that you perform a data analysis. First, you get the data in a form that you can work with. Chapter 2 describes the reshape framework for restructuring data. Second, you plot the data to get a feel for what is going on. Chapter 3 introduces the layered grammar of graphics. Third, you iterate between graphics and models to build a succinct quantitative summary of the data. Chapter 4 introduces some strategies for visualising models. Finally, you look back at what you have done, and contemplate what tools you need to do better in the future. Chapter 5 summarises the impact of my work and my plans for the future.