Learning Objectives

  • Define the individual and group units of analysis and explain the role they play in the ecological and reductionist fallacies.
  • Name and illustrate the three different longitudinal designs.
  • Give an example of a nomothetic and of an idiographic causal explanation.
  • Discuss the role of the counterfactual in nomothetic causal explanation.
  • List the three criteria for establishing a nomothetic causal relationship and the two cautions that can improve understanding of a causal connection.
  • Contrast the strengths and weaknesses of dealing with nonspuriousness through statistical control and through randomization.
  • Explain the meaning of the expression, “correlation does not prove causation.”
  • Name two challenges to using experimental designs and two difficulties with identifying idiographic causal explanations.