A very wide range of research methods are used in psychology.

Some of the approaches include:

• Laboratory experimentation
• Correlational research
• Observational study , in which researchers study a population while attempting to change as little as possible.
• Experimental study , in which researchers change a variable in the group being studied.
• Psychometrics
• Prospective study , in which a study samples subjects as the experiment progresses. Cf. Retrospective study.
• Retrospective study , in which data is collected on subjects' histories at one time. Cf. Prospective study.
• Longitudinal study, in which subjects are studied over a course of time. Cf. Cross-sectional study.
• Cross-sectional study, in which a snapshot of the population is assumed to represent individuals as they progress through life. See also Longitudinal study.
• Meta analysis
• Qualitative research
• Computer simulation
• Concepts and Terms