Making accurate guesses requires groundwork. The statistician must do the following in order to make an educated, better‐than‐chance hunch: Gather data (numerical information). Organize the data (sometimes in a pictorial). Analyze the data (using tests of significance and so forth). This book shows you how to do precisely these procedures and how to use your analysis to draw an inference—an educated statistical guess—to solve a particular problem. While these steps may appear simple (and indeed some of them are), sound statistical method requires that you perform them in certain prescribed ways. Those ways are the heart and soul of statistics.