Statistics is the science of collecting, organizing, and interpreting numerical facts, which we call data. Data bombards us in everyday life. Most of us associate statistics with the bits of data that appear in news reports: baseball batting averages, imported car sales, the latest poll of the president’s popularity, and the average high temperature for today. Advertisements often claim that data show the superiority of the advertiser’s product. All sides in public debates about economics, education, and social policy argue from data.
Yet the usefulness of statistics goes far beyond these everyday examples.
The study and collection of data are important in the work of many professions, so that training in the science of statistics is valuable preparation for a variety of careers. Each month, for example, government statistical offices release the latest numerical information on unemployment and inflation. Economists and financial advisors as well as policy makers in government and business study these data to make informed decisions. Doctors must understand the origin and trustworthiness of the data that appear in medical journals if they are to offer their patients the most effective treatment. Politicians rely on data from polls of public opinion.
Market research data that reveal consumer tastes influence business decisions. Farmers study data from field trials of new crop varieties. Engineers gather data on the quality and reliability of manufactured products. Most areas of academic study make use of numbers, and therefore also make use of the method of statistics.
We can no more escape data than we can avoid the use of words. Just as words on a page are meaningless to the illiterate or confusing to the partially educated, so data do not interpret themselves but must be read with understanding.
A writer can arrange words into convincing arguments or incoherent nonsense. Similarly, you can manipulate data to be compelling, misleading, or simply irrelevant. Numerical literacy, the ability to follow and understand numerical arguments is important for everyone. The ability to express oneself numerically, to be an author rather than just a reader is a vital skill in many professions and areas of study. The study of statistics is therefore essential to a sound education. We must learn how to read data, critically and with comprehension; we must learn how to produce data that provide clear answers to important question; and we must learn sound methods for drawing trustworthy conclusions based on data as well as acquire ability to effectively communicate valid conclusions.
Statistics teaches you how to gather, organize, and analyze data, and then to infer the underlying reality from these data. It is a powerful intellectual method that is applied in many contexts and most disciplines. Persons in industry and government make decisions that are increasingly dependent upon the collection and interpretation of data, and employers demand greater quantitative sophistication from their employees (or prospective employees). Indeed, in almost every aspect of our daily lives we confront data and make judgments based on them, about issues ranging from airline safety to the spread of AIDS. It is now clear that the Challenger disaster never would have occurred if a statistically wise person had seen the data. This did not have to be a statistician, but one (say an engineer) with enough statistical literacy to see the strong relationship between the temperature and the failure rate of the O-rings.
H.G. Wells anticipated that statistical thinking (numerical literacy) would one day be as necessary for efficient citizenship as the ability to read and write. Many individuals and professional groups think that day has come. One individual has written that:
“It is widely agreed that the critical reading and analysis of texts, the methodology of experimental science, and the deductive reasoning of mathematics are broad intellectual methods that should be part of a general education. It is now claimed by some that reasoning from numerical data — that is statistics — deserves a similar stature.
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The influential National Science Board has suggested “elementary statistics and probability should now be considered fundamental for all high school students.”
Statistics students learn to define problems, to think critically, to analyze and to synthesize which prepares them to explore widely throughout their professional lives, and to be creative and productive .
