ABSTRACT
This chapter discusses methods for exploration and visualization of categorical data. It looks at ways to visualize the distribution shapes of univariate categorical data. The chapter also discusses some common discrete distributions and explores how to estimate their parameters. Two of the most common discrete distributions are the binomial and the Poisson. The chapter describes how one can assess the distributions of categorical data using the Poissonness plot, the binomialness plot, and the hanging rootogram. When the variables are categorical, then they are often aggregated and the frequencies are displayed in the form of a contingency table. The chapter explains visualization of cell frequencies in contingency tables. It shows how to visualize univariate cell counts using bar plots and spine plots. Mosaic plots and sieve plots were used to understand both of the variables in two-way tables. The chapter also explains an illustration of the log odds ratio plot.
