Statistics. Why does this single word terrify so many of today’s students? The mere mention of this word in the classroom causes a glassy-eyed, deer-in-the-headlights reaction across a sea of faces. In one form or another, the topic of statistics has been torturing innocent students for hundreds of years. You would think the word statistics had been derived from the Latin words sta, meaning “Why” and tistics, meaning “Do I have to take this %#!$@*% class?” But it really doesn’t have to be this way. The term “stat” needn’t be a four-letter word in the minds of our students.
As you read this paragraph, you’re probably wondering what this book can do for you. Well, it’s written by people (that’s us) who (a) clearly remember being in your shoes as a student (even if it was in the previous century), (b) sympathize with your current dilemma (we can feel your pain), and (c) have learned a thing or two over many years of teaching (those many hours of tutorials were not for naught). The result of this experience has allowed us to discover ways to walk you through many of the concepts that traditionally frustrate students. Armed with the tools that you will gain from the many examples and numerous problems explained in detail, this task will not be as daunting as it first appears.
Unfortunately, fancy terms such as inferential statistics, analysis of variance, and hypothesis testing are enough to send many running for the hills. Our goal has been to show that these complicated terms are really used to describe ordinary, straight-forward concepts. By applying many of the techniques to everyday (and sometimes humorous) examples, we have attempted to show that not only is statistics a topic that anyone can master, but it can also actually make sense and be helpful in numerous situations.
So hold on to your hats, we’re about to take a wild ride into the realm of numbers, inequalities, and, oh yes, don’t forget all those Greek symbols! You will see equations that look like the Chinese alphabet at first glance, but can, in fact, be simplified into plain English. The step-by-step description of each problem will help you break down the process into manageable pieces. As you work the example problems on your own, you will gain confidence and success in your abilities to put numbers to work to provide usable information. And, guess what, that is sometimes how statisticians are born!
How This Book Is Organized
The book is organized into three parts:
In Part 1, The Basics, we start from the very beginning without any assumptions of prior knowledge. In this part, we dive into the world of data and learn about the different types of data and the variety of measurement scales that we can use. We also cover how to display data graphically, both manually and with the help of Microsoft Excel. We wrap up Part 1 with learning how to calculate descriptive statistics, such as the mean and standard deviation.
In Part 2, Probability Topics, we introduce the scary world of probability theory. Once again, we assume you have no prior knowledge of this topic (or if you did, we assume you buried it in the deep recesses of your brain, hoping to never uncover it). An important topic in this part is learning how to count the number of events, which can really improve your poker skills. After easing you into the basics, we gently slide into probability distributions, such as the normal and binomial. Once you master these, we have set the stage for Part 3.
In Part 3, Inferential Statistics, we start off learning about sampling procedures and the way samples behave statistically. When these concepts are understood, we start acting like real statisticians by making estimates of populations using confidence intervals. By this time, your own mother wouldn’t recognize you! We’ll top Part 3 off with a procedure that’s near and dear to every statistician’s heart–hypothesis testing. With this tool, you can do things like make bold comparisons between the male and female population. We’ll leave that one to you.
Extras
Throughout this book, you will come across various sidebars that provide a helping hand when things seem to get a little tough. Many are based on our experience as teachers with the concepts that we have found to cause students the most difficulty.
DEFINITION
These are definitions of statistical jargon explained in a nonthreatening manner, which will help to clarify important concepts. You’ll find that their bark is often far worse than their bite.
RANDOM THOUGHTS
In these sidebars we will give you insights that we find interesting (and hopefully you will, too!) about the current topic. Statistics is full of little-known facts that can help relieve the intensity of the topic at hand.
BOB’S BASICS
These are tips and insights that we have accumulated over the years of helping students master a particular topic. The goal here is to have that light bulb in the brain go off, resulting in the feeling of “I got it!”
WRONG NUMBER
These are warnings of potential pitfalls lying in wait for an unsuspecting student to fall into. By taking note of these, you’ll avoid the same traps that have ensnarled many of your predecessors.
TEST YOUR KNOWLEDGE
In these sidebars we will give you an interesting application to the concept that we just covered so you can relate it to real world applications. We will also ask you if you see any connection between the topic covered and the application given in this sidebar. It is actually fun!
Acknowledgments
There are many people whom I am indebted to for helping me with this project. I’d like to thank Jessica Faust for her guidance and expertise to get me on track in the beginning, Mike Sanders for going easy on me with his initial feedback, and Nancy Lewis, for her valuable opinions during the writing process. I’d also like to thank Mike Thomas and Nancy Wagner for their helpful suggestions with the second edition.
To my colleague and friend, Dr. Patricia Buhler, who introduced me to the publishing industry, convinced me to take on this project, and encouraged me throughout the writing process. This all started with you, Pat.
To my in-laws, Lindsay and Marge, who never failed to ask me what chapter I was writing, which motivated me to stay on schedule. Your commitment to each other is a true inspiration for all of us.
To my boss of 10 years at Goldey-Beacom College, Joyce Jones, who rearranged my teaching schedule to accommodate my deadlines. Life at GBC will never be the same after you retire, Joyce. I am really going to miss you. Thank you for your constant support over the years. You have been a great boss and a true friend.
To my students who make teaching a pleasure. The lessons that I have leaned over the years about teaching were invaluable to me as I wrote this book. Without all of you, I would never have had the opportunity to be an author.
To my children, Christin, Brian, and John, and my stepchildren, Katie, Sam, and Jeff, for your interest in this book and your willingness to let me use your antics as examples in many of the chapters.
And most importantly, to my wife, Debbie, who made this a team effort with all the hours she spent contributing ideas, proofreading manuscripts, editing figures, and giving up family time to help me stay on schedule. Deb’s excitement over my opportunity to write this book gave me the courage to accept this challenge. Deb was also the inspiration for many of the examples used in the book, allowing me to share experiences from our wonderful life together. Thank you for your love and your patience with me while writing this book.
—Bob Donnelly Jr., PhD
I would like to thank Jan Lynn, who helped me patiently throughout this process, never hesitated to provide me with advice, and answered my numerous questions. I also would like to thank Kayla Dugger, Alexandra Elliott, and Jerrell Cassady for their careful review and edit of the manuscript. Furthermore, I would like to thank Jessica Faust for all her help with this process and for arranging everything for me and connecting me with the editors I needed to work with.
To my colleague and friend, the late Dr. Robert Donnelly Jr., his wife Debbie, and their children. Bob passed away in June 2014. His sudden death was a shock to all of us. He left a hole that can’t be filled. His friendly personality, his sense of humor, and his knowledge and extensive experiences are just a few of his traits that we all miss immensely.
To my family: my parents, my husband, my brothers, my mother-in-law, my sisters- and brothers-in-law, my nieces and nephew, my nieces- and nephew-in-law, my cousins, my uncles and aunts, and all my family, for your support throughout this process and for being there for me all the time. I’m blessed to have every one of you in my life. You are such a great and supportive family, and I could not have asked for anything more.
To my colleague and dear friend, Dr. Patricia Buhler, who recommended me to this project, and for her continuous help, support, and advice throughout the years. I’m blessed to have you as a friend, Pat!
To the academic dean at Goldey-Beacom College, Dean Alison White, for her accommodation to my teaching schedule and for going the extra mile to help us. To Dr. Gary Wirt, the President of Goldey-Beacom College for his support and accommodation. Dr. Wirt and Dean White have their doors open for us all the time, listening to our concerns and addressing them as fast as they can.
To my research assistant, Mary Elizabeth Rivers, who carefully reviewed the manuscript. Mary ensured that all equations and calculations were correct, she proofread the manuscript, and she reviewed the graphs and provided useful ideas.
To my students, who made teaching a pleasant experience, who enriched the classroom with their valuable comments and questions, and who made me an experienced teacher.
And above all, to the most important people in my life, my shining stars, whose love and support, patience and understanding, and passion and smiles I could not live without. Your existence in my life gives me the strength and the support to handle anything that comes my way. You are the pillars of my life and my life is meaningless without you! My shining stars are the best children any parent could ever dream of and I’m very blessed to have them. Loving you and looking at you gives me the strength to write this book. I could not have done it without you, my shining stars. I love you more than the whole world.
—Fatma Abdel-Raouf, PhD
Special Thanks to the Technical Reviewer
Idiot’s Guides: Statistics, Third Edition, was reviewed by an expert who double-checked the accuracy of what you’ll learn here, to help us ensure this book gives you everything you need to know about statistics. Special thanks are extended to Jerrell Cassady, PhD. Jerrell is a Professor of Psychology in the Department of Educational Psychology at Ball State University. He is also the Director of Graduate Programs in Educational Psychology and the Co-Director of the Research Design Studio. Jerrell was assisted by Christopher Thomas, MS, a doctoral candidate in the Department of Educational Psychology and a research fellow in the Research Design Studio.
Trademarks
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