ABSTRACT
This introductory chapter gives an overview of the key concepts discussed in the subsequent chapters of this book. The book presents articles which use two primary statistical methods to understand the relationship between variables: correlation and regression. In the book, researchers use fancy statistical terms like multiple correlation, or amount of variance explained, or multiple linear regression. But, at the end of the day, all of these techniques are about how two (or more) variables are related, how A relates to B. It introduces the idea of meta-analysis. This is a procedure for combining the results of multiple studies, possibly many studies. Meta-analysis is becoming a hallmark of the development of scientific knowledge. Research articles with a meta-analysis can be very complicated because they talk about tens if not hundreds of studies. But how is A related to B? This is still the fundamental question a meta-analysis is trying to answer.
