Learning Objectives

  • List the essential components of a true experimental design. 
  • Identify the consequences of using random assignment in an experiment.
  • Distinguish the concepts of random assignment (randomization) and random sampling.
  • Explain the advantages and disadvantages of using quasi-experimental and experimental designs.
  • Define five of the threats to internal validity in research designs and explain the extent to which each is a source of concern in true experimental designs.
  • Compare the influences on external validity (generalizability) in experimental design to those on internal validity (causal validity).
  • Discuss the most distinctive ethical challenges in experimental research.