- Differentiate between types of research (descriptive, experimental, and correlational)
- Explain the strengths and weaknesses of different types of research (case studies, naturalistic observation, and surveys)
- Explain the strengths and weaknesses of different types of research (archival, longitudinal, and cross-sectional research)
Types of Research
There are many research methods available to psychologists in their efforts to understand, describe, and explain behavior and the cognitive and biological processes that underlie it. Some methods rely on observational techniques. Other approaches involve interactions between the researcher and the individuals who are being studied—ranging from a series of simple questions to extensive, in-depth interviews—to well-controlled experiments.
The three main categories of psychological research are descriptive, correlational, and experimental research.
- Descriptive studies are those that are based on observations and do not test specific relationships between variables. These studies are used to describe general or specific behaviors and attributes that are observed and measured. Descriptive studies are particularly valuable when designing an experiment would be premature, or when it may be unethical to conduct an experiment. Studies that rely primarily on observation produce incredible amounts of information, but the ability to apply this information to the general public might be limited.
- Correlational research is used to formally test whether a relationship exists between two or more variables. For example, does eating breakfast correlate with better performance in early morning classes? Correlational research can find a relationship between two variables, but it cannot claim that one thing causes another. Correlational and experimental research both typically use hypothesis testing, whereas descriptive research does not.
- Experimental research investigates cause-and-effect relationships between variables. In an experimental study, the researcher manipulates one or more variables to observe their impact on other variables, while controlling for other factors that may influence the results. They use hypothesis testing to make inferences about how one condition might affect another. In experimental research, researchers can test for cause and effect, but there can be hidden influences on the experiment and experiments are often conducted in artificial settings. This calls into question the validity of experimental findings with regard to how they would apply in real-world settings. In addition, many of the questions that psychologists would like to answer cannot be pursued through experimental research because of ethical concerns.
Types of Research Overview
Table 1 displays a quick overview of the characteristics of each research design.
| Table 1. Characteristics of Descriptive, Experimental, and Correlational Research |
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| Research Design | Characteristic | |
| Descriptive | Allows researchers to observe and gather information about a topic | A psychologist observes and records the behavior of children in a playground to study the effects of peer influence on social interactions. The researcher does not intervene or manipulate any variables but simply observes and takes notes. |
| Correlational | Tests a hypothesis to determine whether a relationship exists between two or more variables | Researchers examine the relationship between self-esteem and academic achievement by collecting data on a sample of high school students. They measure both self-esteem and academic performance and analyze whether there is a correlation between the two variables. |
| Experimental | Is the only way to determine if a cause-and-effect relationship exists between variables | Researchers investigate the effects of sleep deprivation on memory by randomly assigning participants to either a sleep-deprived group or a well-rested group. Both groups are given a memory task, and the researchers compare their performance. |
Each of these research methods has unique strengths and weaknesses, and each method may be best suited for answering certain types of research questions. There are also more than just these three types of research methods, and there is oftentimes overlap between the methods used. Additionally, psychologists use a variety of tools to help them conduct research.
These next few pages will focus on the various types of descriptive research and some of the tools psychologists use to conduct as you’ll learn more about correlational and experimental research in the next section.