A wide range of research methods are used in psychology.

Most methods gather either qualitative data, quantitative data or both. Here are the main research methods:

• Laboratory experiment
• Field experiment
• Quasi experiment
• Correlational
• Observation, can be naturalistic, participant or controlled.
• Case study
• Interview, can be structured or unstructured.
• Statistical survey
• 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
• Content analysis