The second step in a psychology study is to select the research methods that will be used and then collect the data. The research method a researcher chooses depends largely on exactly what they are studying. There are two basic types of research methods—descriptive research and experimental research.
Descriptive Research Methods
Descriptive research such as case studies, naturalistic observations and surveys are often used when it would be impossible or difficult to conduct an experiment. These methods are best used to describe different aspects of a behavior or psychological phenomenon. Once a researcher has collected data using descriptive methods, a correlational study can then be used to look at how the variables are related.
Experimental Research Methods
Experimental methods are used to demonstrate causal relationships between variables. In an experiment, the researcher systematically manipulates a variable of interest (known as the independent variable) and measures the effect on another variable (known as the dependent variable). Unlike correlational studies, which can only be used to determine if there is a relationship between two variables, experimental methods can be used to determine the actual nature of the relationship. That is to say, if changes in one variable actually cause another to change.