This book provides an elementary description of statistics for those who do not want to spend too much time and effort in learning its theory. It presents a dialogue between a professor of statistics and a student, who is not good at mathematics but is interested in statistics. The dialogue is given in a very straightforward way and is easy to follow. Nevertheless, the book covers important concepts of statistics through practical examples.
Statistical methods are widely employed in various science fields, including medical and epidemic research, agricultural experiments, quality control, marketing, and economics. These methods play essential roles in many branches of not only natural science but also humanities and social science. For example, economic indicators such as gross national product and price indices provide us some information about the conditions of the economic activities and price level of a country. By applying the method of hypothesis testing, we can determine whether the effect of a newly developed medicine is significant.
Although statistics has some practical aspects, its theory involves rigorous mathematics, which may prove difficult for those studying this subject. However, this can be viewed as an advantage of statistics because mathematics is the “common language of the sciences.” As this common language is used in various branches of science, statistics is applicable in many fields. Regardless of academic background, anyone can study and apply statistics to solve problems without converting them to new ones.
This book provides the first step in the exploration of statistics. By enjoying the dialogues between the professor of statistics and the student in this book, you can immerse yourself in a basic course of elementary statistics. More specifically, the course begins with the notion of “population and sample,” which represents the basic framework of statistics. You can also learn some typical concepts in summary statistics, including mean, variance, standard deviation, correlation, and regression. Moreover, the book covers the fundamentals of normal and binomial distributions. Through practical examples involving the application of these concepts, the book is able to describe several aspects of statistical inference. More specifically, through an example of an investigation into viewing rates, you can learn the essence of interval estimation and confidence intervals. By familiarizing yourself with an example of a clinical trial, you can gain an understanding of the basic ideas of statistical hypothesis testing.
The book consists of four chapters. Chapter 1 explains statistics used in our society with a focus on public opinion survey and life assurance. Chapter 2 discusses how to use graphs to understand data. This chapter also introduces normal distribution. Chapter 3 presents the concepts of variance, correlation, and regression. Chapter 4 is devoted to statistical inference.
Through this book, I hope that you can obtain knowledge that will be helpful in your future endeavors.
(Written by KURATA Hiroshi, Professor, Graduate School of Arts and Sciences / 2022)