Methods of Conducting Psychological Research

As psychology is based on the knowledge gathered through observation and measurement, psychologists use a variety of methods to study mental processes and behaviors.

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The variety of methods used by psychologists are:

1. Experimental Method

In the experimental method, the researcher studies the effect of change of one variable in another variable while keeping the other variables constant.


Variables are anything that can be measured and have different values. There are two types of variables, dependent variables, and independent variables. In an experiment, the researcher manipulates the independent variable to study the effect/change in the dependent variable.

For example, an experimenter wants to study the effect of a particular drug on a person’s behavior. In this case, the drug administered is an independent variable, whereas the person’s behavior is a dependent variable. Here, the person’s behavior is heavily dependent upon the drug administered (i.e., independent variable), so the name dependent variable is obvious.

Control Group and Experimental Group

The control group serves as a baseline in the study. A baseline i.e behavior of a particular person before giving the drug to the person is observed. Then the behavior of the person after the intake of that particular drug is observed. This before and after method helps to establish the relationship among the variables.

2. Observational Method

The observational method is the process of collecting data by watching what people do. After repeated observations, the psychologists can draw the inference regarding the cause of the behavior. There are various types of observational methods used in psychology.

i. Naturalistic Observation

In this method, the researchers do not manipulate the independent variables but observe the naturally occurring variations. The famous work of Jane Goodall’s work studying the behavior of chimpanzees is an example of naturalistic observation. One advantage of naturalistic observation is that the researcher can get a sample of what people do in their natural habitat. Similarly, one of the clear disadvantages of naturalistic observation is that the researcher does not have control over any factors.

ii. Controlled Observation

Controlled observation is a type of observation made under structured conditions. Generally, controlled observations are carried out in the laboratory where the researcher can have control over the variables. Bandura’s method to study social learning theory (Bobo Doll experiment) was an example of controlled observation.

iii. Participant Observation

Participant observation is a type of naturalistic observation where the researcher also becomes part of the group that they are studying. This is generally done to get a better insight into their lives. One of the main disadvantages of participant observation is that the presence of the researcher may alter the behavior of the participants.

3. Survey Research

In the survey method, data are collected by asking a sample of people (representing a larger population) about their behavior, thoughts, or attitudes. The questions are asked questions either in person, on paper, by phone, or online.

4. Case Study

Contrary to the survey method, the case study is an in-depth, intensive investigation of a single individual, group, or event.

Usually, case studies include psychological assessments (generally consists of scientifically designed sets of questions) from which the researcher gets insights about the behavior and personality of the individual or the group.

Sigmund Freud developed his theories of psychoanalysis through the case studies of his patients. One of the significant drawbacks of case studies is that each individual has unique behavior and personality. It is almost impossible to make valid generalizations to a larger group of people.

5. Correlational Research

In the correlational method, the researchers measure the relationship between the two variables. In this method, the study is carried out to find out whether the variables are associated or correlated. The correlation between them is expressed through mathematical static called a correlation coefficient.

The value of the correlation coefficient can range from +1.0 to -1.0. When the value of the correlation coefficient is close to +1.0, it is called a positive correlation. Similarly, when the correlation coefficient value is close to -1.0, it is called a negative correlation.

A study to determine whether smoking causes cancer, the variables would be smoking and cancer, is an example of correlational research.

Type of CorrelationValue of Correlation CoefficientRemaks
Positive Correlation0 to +1.0.Variables vary in the same direction
Negative Correlation0 to -1.0.Variables vary in the opposite direction
Zero Correlation0No relationship among the variables.


i. The number of hours spent studying and test scores is an example of a positive correlation.
ii. The number of hours spent exercising and the level of body fat is an example of a negative correlation.
iii. The habit of drinking tea and intelligence has no relationship. This is an example of a zero correlation.