What Exactly is Research?
Research studies come in many different forms, and we will discuss several of these forms in more detail in Chapter 5. For now, however, we will focus on two of the most common types of research-correlational research and experimental research.
Correlational research: In correlational research, the goal is to determine whether two or more variables are related. (By the way, “variables” is a term with which you should be familiar. A variable is anything that can take on different values, such as weight, time, and height.) For example, a researcher may be interested in determining whether age is related to weight. In this example, a researcher may discover that age is indeed related to weight because as age increases, weight also increases. If a correlation between two variables is strong enough, knowing about one variable allows a researcher to make a prediction about the other variable. There are several different types of correlations, which will be discussed in more detail in Chapter 5. It is important to point out, however, that a correlation or relationship between two things does not necessarily mean that one thing caused the other.To draw a cause-and-effect conclusion, researchers must use experimental research.This point will be emphasized throughout this book.
Experimental research: In its simplest form, experimental research involves comparing two groups on one outcome measure to test some hypothesis regarding causation. For example, if a researcher is interested in the effects of a new medication on headaches, the researcher would randomly divide a group of people with headaches into two groups. One of the groups, the experimental group, would receive the new medication being tested.The other group, the control group, would receive a placebo medication (i.e., a medication containing a harmless substance, such as sugar, that has no physiological effects). Besides receiving the different medications, the groups would be treated exactly the same so that the research could isolate the effects of the medications. After receiving the medications, both groups would be compared to see whether people in the experimental group had fewer headaches than people in the control group. Assuming this study was properly designed (and properly designed studies will be discussed in detail in later chapters), if people in the experimental group had fewer headaches than people in the control group, the researcher could conclude that the new medication reduces headaches.

In recent years, the results of various research studies have taken center stage in the popular media. No longer is research the private domain of research professors and scientists wearing white lab coats. To the contrary, the results of research studies are frequently reported on the local evening news, CNN, the Internet, and various other media outlets that are accessible to both scientists and nonscientists alike. For example, in recent years, we have all become familiar with research regarding the effects of stress on our psychological well-being, the health benefits of a lowcholesterol diet, the effects of exercise in preventing certain forms of cancer, which automobiles are safest to drive, and the deleterious effects of pollution on global warming. We may have even become familiar with research studies regarding the human genome, the Mars Land Rover, the use of stem cells, and genetic cloning. Not too long ago, it was unlikely that the results of such highly scientific research studies would have been shared with the general public to such a great extent. Despite the accessibility and prevalence of research in today’s society, many people share common misperceptions about exactly what research is, how research can be used, what research can tell us, and the limitations of research. For some people, the term “research” conjures up images of scientists in laboratories watching rats run through mazes or mixing chemicals in test tubes. For other people, the term “research” is associated with telemarketer surveys, or people approaching them at the local shopping mall to “just ask you a few questions about your shopping habits.” In actuality, these stereotypical examples of research are only a small part of what research comprises. It is therefore not surprising that many people are unfamiliar with the various types of research designs, the basics of how research is conducted, what research can be used for, and the limits of using research to answer questions and acquire new knowledge. Rapid Reference 1.1 discusses what we mean by “research” from a scientific perspective. Before addressing these important issues, however, we should first briefly review what science is and how it goes about telling us what we know.