Watch this 5:19 video from Scribbr to learn about research design.
Research types on this page are modeled after some taken from the Encyclopedia of Measurement and Statistics and The SAGE Dictionary of Social Research Methods which can be accessed through SAGE Research Methods.
- Observational: Researchers observe participants but do not attempt to influence them.
- Correlational: Researchers examine how two or more variables are related. It is not possible to tell which variable is affecting the other(s). As you have probably heard, "correlation is not causation."
- Experimental: Researchers control conditions to examine how one variable affects the other(s). Participants are assigned to random groups (at least two). There is a control group that does not experience or receive the variable being examined and a experimental group that does experience or receive the variable being examined. The groups are compared to examine the effect of the variable being investigated.
In experiments, causation can be explored.
- Quasi-experimental: A quasi-experiment is like an experiment, but the groups cannot be assigned. Quasi-experiments use pre-existing groups.
For more information on different methods, check out the SAGE Research Methods visual tool for exploring these topics.
Source: XKCD webcomic, accessed 2/12/2025
