Research studies that do not test specific relationships between variables are called descriptive studies. These studies are used to describe general or specific behaviors and attributes that are observed and measured. In the early stages of research it might be difficult to form a hypothesis, especially when there is not any existing literature in the area. In these situations designing an experiment would be premature, as the question of interest is not yet clearly defined as a hypothesis. Often a researcher will begin with a non-experimental approach, such as a descriptive study, to gather more information about the topic before designing an experiment or correlational study to address a specific hypothesis.
Descriptive research is distinct from correlational research, in which psychologists formally test whether a relationship exists between two or more variables. Experimental research goes a step further beyond descriptive and correlational research and randomly assigns people to different conditions, using hypothesis testing to make inferences about how these conditions affect behavior. Correlational and experimental research both typically use hypothesis testing, whereas descriptive research does not.
Descriptive Research
While descriptive research cannot be generalized beyond the specific object of study, it can help psychologists gain more information about a topic, and formulate hypotheses for future experiments.
Descriptive research can be used to gain a vast, if often inconclusive, amount of information. It has the advantage of studying individuals in their natural environment without the influence of the artificial aspects of an experiment. This approach can also be used to document rare events or conditions that could not be reproduced in a laboratory.
Case Studies
One important kind of descriptive research in psychology is the case study, which uses interviews, observation, or records to gain an in-depth understanding of a single person, group, or phenomenon. Although case studies cannot be generalized to the overall population (as can experimental research), nor can they provide predictive power (as can correlational research), they can provide extensive information for the development of new hypotheses for future testing and provide information about a rare or otherwise difficult-to-study event or condition.