A correlational study is a research design that examines the relationships between two or more variables. It is non-experimental, meaning the experimenter does not manipulate or control any variables.
The goal of correlational research is often to look for relationships, describe these relationships, and then make predictions. Such research can also often be a jumping-off point for future experimental research.
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Verywell / Brianna Gilmartin
Characteristics of Correlational Studies
Correlational studies are often used in psychology and other fields like medicine. Such studies are sometimes used as a preliminary way to gather information about a topic. The method is also helpful if researchers are unable to perform an experiment.
Researchers use correlations to see if a relationship between two or more variables exists, but the variables themselves are not under the control of the researchers.
While correlational research can demonstrate a relationship between variables, it cannot prove that changing one variable will change another. In other words, correlational studies cannot prove cause-and-effect relationships.
When you encounter research that refers to a “link” or an “association” between two things, they are most likely talking about a correlational study.
What Do Positive, Negative, and Zero Correlations Mean?
A correlation refers to a relationship between two variables. Correlations can be strong or weak and positive or negative. Sometimes, there is no correlation.
A correlation study can produce three possible outcomes: a positive correlation, a negative correlation, or no correlation. Researchers present the results using a numerical value called the correlation coefficient, a measure of the correlation strength. It can range from -1.00 (negative) to +1.00 (positive). A correlation coefficient of 0 indicates no correlation.
- Positive correlations: Both variables increase or decrease at the same time. A correlation coefficient close to +1.00 indicates a strong positive correlation.
- Negative correlations: As the amount of one variable increases, the other decreases (and vice versa). A correlation coefficient close to -1.00 indicates a strong negative correlation.
- No correlation: There is no relationship between the two variables. A correlation coefficient of 0 indicates no correlation.
The variables in a correlational study are what the researcher measures. Once measured, researchers can then use statistical analysis to determine the existence, strength, and direction of the relationship. However, while correlational studies can say that variable X and variable Y have a relationship, it does not mean that X causes Y.
How Psychologists Use Correlational Research
There are three types of correlational research: naturalistic observation, the survey method, and archival research. Each type has its own purpose, as well as its pros and cons.
Naturalistic Observation
The naturalistic observation method involves observing and recording variables of interest in a natural setting without interference or manipulation.
Advantages
Can inspire ideas for further research
Option if lab experiment not available
Variables are viewed in natural setting
Disadvantages
Can be time-consuming and expensive
Extraneous variables can’t be controlled
No scientific control of variables
Subjects might behave differently if aware of being observed
This method is well-suited to studies where researchers want to see how variables behave in their natural setting or state. Inspiration can then be drawn from the observations to inform future avenues of research.
In some cases, it might be the only method available to researchers; for example, if lab experimentation would be precluded by access, resources, or ethics. Naturalistic observation is preferable to not being able to conduct research at all, but the method can be costly and usually takes a lot of time.
Naturalistic observation presents several challenges for researchers. For one, it does not allow them to control or influence the variables in any way nor can they change any possible external variables.
However, this does not mean that researchers will get reliable data from watching the variables, or that the information they gather will be free from bias.
For example, study subjects might act differently if they know that they are being watched. The researchers might not be aware that the behavior that they are observing is not necessarily the subject’s natural state (i.e., how they would act if they did not know they were being watched).
Researchers also need to be aware of their biases, which can affect the observation and interpretation of a subject’s behavior.
Surveys
Surveys and questionnaires are some of the most common methods used for psychological research. The survey method involves having a random sample of participants complete a survey, test, or questionnaire related to the variables of interest. Random sampling is vital to the generalizability of a survey’s results.
Disadvantages
Results can be affected by poor survey questions
Results can be affected by unrepresentative sample
Outcomes can be affected by participants
If researchers need to gather a large amount of data in a short period of time, a survey is likely to be the fastest, easiest, and cheapest option.
It’s also a flexible method because it lets researchers create data-gathering tools that will help ensure they get the information they need (survey responses) from all the sources they want to use (a random sample of participants taking the survey).
Survey data might be cost-efficient and easy to obtain, but it has its downsides. For one, the data is not always reliable, particularly if the survey questions are poorly written or the overall design or delivery is weak. Specific faults, such as unrepresented or underrepresented samples, also affect the data.
The use of surveys relies on participants to provide useful data. Researchers need to be aware of the specific factors related to the people taking the survey that will affect its outcome.
For example, some people might struggle to understand the questions. A person might answer a particular way to try to please the researchers or to try to control how the researchers perceive them (such as trying to make themselves “look better”).
Sometimes, respondents might not even realize that their answers are incorrect or misleading because of mistaken memories.
Archival Research
Many areas of psychological research benefit from analyzing studies that were conducted long ago by other researchers, as well as reviewing historical records and case studies.
Using records, databases, and libraries that are publicly accessible or accessible through their institution can help researchers who might not have a lot of money to support their research efforts.
Free and low-cost resources are available to researchers at all levels through academic institutions, museums, and data repositories around the world.
Another potential benefit is that these sources often provide an enormous amount of data that was collected over a very long period of time, which can give researchers a way to view trends, relationships, and outcomes related to their research.
While the inability to change variables can be a disadvantage of some methods, it can be a benefit of archival research. That said, using historical records or information that was collected a long time ago also presents challenges.
- Missing information: For one, important information might be missing or incomplete, and some aspects of older studies might not be useful to researchers in a modern context.
- Unreliable information: A primary issue with archival research is reliability. When reviewing old research, little information might be available about who conducted it, how the study was designed, who participated in it, and how data were collected and interpreted.
- Ethical problems: Researchers can also face ethical quandaries—for example, should modern researchers use data from studies that were conducted unethically or with questionable ethics?
How Correlational Studies Differ From Experiments
The difference between a correlational study and an experimental study involves the manipulation of variables.
Correlational Studies
No manipulation of variables
Used to detect the presence and strength of relationships between variables
Can show positive, negative, or zero correlation
Good for identifying patterns and making predictions
Experiments
Variables are systematically controlled and varied
Used to determine cause-and-effect relationships between variables
Can show if changes in one variable lead to changes in another
Good for determining causal relationships
If the study involves the systematic manipulation of a variable’s levels, it is an experimental study. If researchers are measuring what is already present without actually changing the variables, then it is a correlational study.
Correlation Doesn’t Equal Causation
You’ve probably heard the phrase, “correlation does not equal causation.” This means that while correlational research can suggest that there is a relationship between two variables, it cannot prove that one variable will change another.
For example, researchers might perform a correlational study that suggests a relationship between academic success and self-esteem. However, the study cannot show that academic success changes a person’s self-esteem.
To determine why the relationship exists, researchers would need to consider and experiment with other variables, such as the subject’s social relationships, cognitive abilities, personality, and socioeconomic status.
Key Takeaways
- Correlational studies in psychology describe relationships between variables, but cannot be used to establish that changes in one variable cause changes in another.
- Correlational research can be conducted using naturalistic observation, surveys, or archival records.
- It’s important to remember that correlation does not equal causation. Correlational studies can tell you if there is a relationship between variables, but only experimental studies can indicate whether it is a causal relationship.
