Statistics is the process of making complex data structures amenable to human cognition. The chapter introduces the mean, a measure of the central tendency of a distribution. The mean is discussed as a “model”, in the sense that it provides a simplified representation of a set of numbers that is easier to grasp than the entire set of numbers. Another important “model” is the standard deviation, which measures the spread of a distribution. Alongside a discussion of these basic descriptive statistics, the uniform distribution and normal distribution (Gaussian) are introduced to the reader, together with the important fundamental distinction between sample estimates and population parameters. The chapter concludes with a descriptive analysis of how “good” or “bad” certain words are (emotional valence).