Experimental vs. Observational

Experimental Studies

  • Researcher manipulates the independent variable
  • Random assignment to conditions
  • Can establish causation
  • High internal validity
Controlled Causal

Observational Studies

  • Researcher observes naturally occurring variation
  • No random assignment
  • Can establish correlation
  • High ecological validity
Naturalistic Correlational

Neither approach is inherently "better" — the right choice depends on your research question.