Research design is a fundamental basis of many studies, including psychology. Chapter 2 mainly talks about the needs, different types, and arising issues of research designs in the field of psychology. In addition, at the end of the chapter, the textbook shows how data and results obtained from studies are analyzed and evaluated.
Before I read the chapter, I thought that research study in psychology is all about generating surveys and compiling the responses, which are then analyzed statistically. In my opinion, psychology is the study of behavior. It has never crossed my mind that the research design might include quantitative measurements. How can behavior be interpreted with numbers?
A type of research design mentioned in the chapter then answered my question. Correlational design is one of the research methods, which utilizes two variables that are associated with each other. Correlation of the two variables means that they relate to each other statistically but not interpersonally. With correlational design, psychologists are able to suggest one's behavior by correlating it with other related factors.
I found an interesting video, which gives a good example to plan a research design. In here, two researchers are debating on the approaches to study children with ADHD.
Good summary of what some might view as a "boring" chapter of the book (although that is not my personal view). Quantifying behavior is difficult and tricky!