Correlational research is a type of non-experimental research method, in which a researcher measures two variables, understands and assess the statistical relationship between them with no influence from any extraneous variable.

Our mind can do some brilliant things. For example, it can memorize the jingle of a pizza truck. Louder the jingle, closer is the pizza truck to us. Who taught us that? Nobody! We relied on our understanding and came to a conclusion. We just don’t stop there, do we? If there are multiple pizza trucks in the area and each one has a different jingle, we would be able to memorize it all and relate the jingle to its pizza truck.

This is precisely what correlational research is, establishing a relationship between two variables, “jingle” and “distance of the truck” in this particular example. Correlational research is looking for variables that seem to interact with each other so that when you see one variable changing, you have a fair idea how the other variable will change.

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The correlation between two variables is shown through correlation coefficient (A correlation coefficient is a statistical measure that calculates the strength of the relationship between two variables), that is a value measured between -1 and +1. When the correlation coefficient is close to +1 then there is a positive correlation between the two variables and the value is close to -1, then there is a negative correlation between the two variables and when the value is close to zero then there is no relationship between the two variables.

Let us take an example to understand correlational research.

Consider hypothetically, a researcher is studying a correlation between cancer and marriage. In this study, there are two variables: cancer and marriage. Let us say marriage has a negative correlation with cancer. This means that people who are married are less likely to develop cancer.

However, this doesn’t necessarily mean that marriage directly avoids cancer. In correlational research, it is not possible to establish the fact, what causes what. It is a misconception that correlational research involves two quantitative variables, however the fact is two variables are measured, but neither is changed. This is true independent of whether the variables are quantitative or categorical.

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Essentially there are three types of correlational research that have been identified:

**1. Positive correlation:** A positive correlation between two variables is when an increase in one variable leads to an increase in the other variable and a decrease in one variable will see a decrease in the other variable. For example, the amount of money a person has might positively correlate with the number of cars he has.

**2. Negative correlation:** A negative correlation is quite literally the opposite of positive correlation. This means, if there is an increase in one variable, the second variable will show a decrease and vice versa.

For example, the level of being educated might negatively correlate with the crime rate when an increase in one variable leads to a decrease in another and vice versa. This means if in some ways the level of education in a country is improved, it can lead to lowering the crime rates. Please note, that this doesn’t mean that lack of education leads to crimes. This means lack of education and crime is believed to have a common reason: poverty.

**3. No correlation:** In this third type, two variables are not correlated. This means a change in one variable may not necessarily see a change in the other variable. For example, being a millionaire and happiness is not correlated. This means an increase in money doesn’t lead to happiness.

The distinctive feature of correlational research is that neither of the variable involved is manipulated. It doesn’t matter how or where the variables are measured. A researcher could observe participants in a closed environment or in a public setting.

There are two data collection methods that are used to collect information in correlational research.

**Naturalistic Observation **

Naturalistic observation is a way of data collection in which people’s behavior is observed in their natural environment, in which they typically exist. This method is a type of field research. It could mean a researcher might be observing people in a grocery store, at the cinema, playground or similar places.

Researchers who are usually involved in this type of data collection make observations as unobtrusively as possible so that the participants who are involved in the study are not aware that they are being observed else they might deviate from being their natural self.

Ethically this method is acceptable if the participants remain anonymous and if the study is conducted in public setting, where people would not normally have an expectation of complete privacy. As mentioned previously, taking an example of the grocery store where people can be observed while collecting an item from isle and putting in the shopping bags. This is ethically acceptable and that the reason most researchers choose public settings for recording their observation. This data collection method could be both qualitative or quantitative.

**Archival Data **

Another approach to correlational data is the use of archival data. Archival data is the data that has been previously collected by doing similar kind of research. Archival data is usually made available through primary research.

In contrary to naturalistic observation, the information collected through archived data can be quite straightforward. For example, counting the number of people name Richard in the various states of America based on social security records is quite straightforward.