What does statistics mean to you? Does it bring to mind batting averages, Gallup polls, unemployment figures, or numerical distortions of facts (lying with statistics!)? Or is it simply a college requirement you have to complete? We hope to persuade you that statistics is a meaningful, useful science whose broad scope of applications to business, government, and the physical and social sciences is almost limitless. We also want to show that statistics can lie only when they are misapplied. Finally, we wish to demonstrate the key role statistics plays in critical thinking—whether in the classroom, on the job, or in everyday life. Our objective is to leave you with the impression that the time you spend studying this subject will repay you in many ways.

The Random House College Dictionary defines statistics as “the science that deals with the collection, classification, analysis, and interpretation of information or data.” Thus, a statistician isn’t just someone who calculates batting averages at baseball games or tabulates the results of a Gallup poll. Professional statisticians are trained in statistical science. That is, they are trained in collecting information in the form of data, evaluating the information, and drawing conclusions from it. Furthermore, statisticians determine what information is relevant in a given problem and whether the conclusions drawn from a study are to be trusted.

In the next section, you’ll see several real-life examples of statistical applications that involve making decisions and drawing conclusions.