In this chapter we explore the statistical software program called R along with the integrated development environment known as RStudio. We provide a brief review of the history of R followed by guidance on how to download and install R and RStudio. Next, we explore features of the program including a basic review of the graphical interface. We then turn to working with basic commands, loading and saving data, and provide examples of working with packages in R.

In this chapter, we discuss the use of simulations for clinical trials. Simulation in statistics generally refers to repeated analyses of randomly generated datasets with known properties. Clinical trial simulation is required to explore, compare, and characterise operating characteristics and statistical properties of adaptive and other innovative trials with complex designs. Clinical trial simulation is an important tool that allows for comparison of different design choices during the planning stage to enhance the quality and feasibility of the trial. While simulations are most frequently used in adaptive and other complex trial designs, they can be applied to fixed trial designs.