Some of the approaches include:

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