Statistics: Short and Simple

Most people seem to have a very negative impression of statistics.  They don’t understand it , don’t trust it, and when pressed will readily admit that they are either intimidated by it or have no interest whatsoever.  When I admit to having taught statistics to business students, even as only an adjunct instructor, looks range from awe to dread that I will say something that will magically give you a headache.  This statistics-phobia seems to be a very common problem.

How many people have I seen walk into a college business statistics class with that “deer in the headlights,” “what have I gotten myself into” look in their eyes?  How many have left it until the last semester before graduation?  How many would have skipped it entirely if it were not required?  These are people who are not the least bit intimidated by batting averages, third down completion percentages, playing the lottery or going to the casino, basketball free throw shooting percentages, or even infant mortality rates.  Yet the very thought of statistics as a subject of study sends shivers down their spines.

Others have said to me, “I would really like to know more about statistics, but I don’t want to spend the time taking a course and working through all of the problems at the end of the chapters; I just want to know a little more about it.”  Most don’t know that it’s possible to learn just a little without getting bogged down in the complexity.

This short book is intended to address these problems, by describing the concepts of statistics without requiring calculations, to give people an idea of what it’s all about in a friendly and accessible way.  The organization is similar to most basic statistics text books, but the emphasis is changed from formulas and calculations to ideas about what is happening and why.  It is more important to know what a standard deviation is and why you might want to calculate one than it is to know how to calculate one.  A simple spreadsheet program on a PC can do the math.

We see almost nightly on the national news stories about what new drugs are being tested, what foods have been shown to be harmful,  what vitamins may prevent cancers, what health practices will allow you to live longer, and what additive that was assumed to be bad for you has now been shown to be not so bad.  Unfortunately statistics like these are all around and people need to know enough to deal with them.  Both in business and in our personal lives knowing about statistics is often the only way to tell what is important from what is just the latest fad.  Without knowing something about the subject, people are exposing themselves to the chance of being confused, or worse,  taken advantage of, by those who can use or misuse statistics to their own advantage.  To put yourself in a stronger position you don’t need to know how to do any calculations.  You just need to have an understanding of the subject, its strengths and weaknesses.

Being familiar with the concepts in this way will make it easier for those planning to take a formal course later and get deeper into it.  It will also make it easier to survive the daily onslaught of news headlines designed to get your attention about the “latest research” through fear or exaggeration.  It will help people at work dealing with programs like total quality management or six sigma, all of which are based in statistics.  I used to tell my students that if they only knew the concepts and the vocabulary they could always remain calm and look into the details later.  If someone at work mentioned standard deviation or chi-square and saw that lost look in their eyes, they were already at a disadvantage in the conversation.

Although most of the math involved in a basic statistics course is no more difficult than algebra, it can serve to distract and confuse people.  Students memorize formulas and miss the point.  They learn to recognize patterns of problems, so that they can “plug and chug” through the calculations.  At the end of the course most people forget the formulas that they crammed into their heads for the exam and are left with nothing but the good feeling of having finally passed the course.

In summary, there is a large number of people who have been exposed to statistics either formally through college requirements or informally through daily references in the news, weather, and sports.  Most are not fully equipped to handle this information.  The current alternatives of taking a formal class or reading a standard text book are not practical.

Here’s what lies ahead.

The first chapter describes the need, how statistics are all around, unavoidable, and surprisingly so common that most people take the situation for granted.

Chapters 2-7 walk through the ability to use statistics descriptively, using simple examples and charts to show the basic concepts.  It begins with some key definitions followed by examples of some “data visualization” techniques.  Subsequent chapters explain the mean and standard deviation, distributions, again with simple examples and figures to illustrate various points.  Chapter 5 on probability (a must for people interested in winning the lottery) is des