• Matched design : between subjects experiment that involves sets of participants matched on a specific characteristic with each member of the set randomly assigned to a different level of the IV
  • Counterbalance : used in within­subject experiments where equal numbers of participants are randomly assigned to different orders of the conditions
  • Latin square : partial counterbalancing technique where the number of orders of conditions used is equal to the number of conditions in the study
  • Factorial design : more than one IV

o Can be more efficient in testing the effects of multiple IV in one experiment o Can also examine the effects of multiple interactions of those IV on the DV

  • Levels of the IV : conditions that participants experience
  • Main effect : test of the differences between all means for each level of an IV in an ANOVA
  • ANOVA : analysis of variance test used for designs with 3 or more sample means
  • Interaction effect : tests the effect of one IV at each level of another IV in an ANOVA
  • Simple effects tests : statistical tests conducted to characterize an interaction effect when one is found in an ANONA
  • Experiment examples : cognitive, biological, social, and developmental o Cognitive : investigates the effects of the color of the objects on a person’s ability to detect objects in visual scenes

o Biological : Causal relationships between biology and behavior

 Interested in the brain activity that occurs when people lie about a crime they have committed

  • Social: a randomly assigned role as a prisoner or guard in a mock prison affected participants’ behavior, was described as an example of a study that may have violated ethical guidelines
  • Developmental: interested in how memory for the location of objects is influenced by the similarity of objects and whether this relationship is the same for different age groups

 

Chapter Summary:

  • Experiments contain an IV that is manipulated and allows for control of alternative explanations of the results o The best research design for testing causal relationships
    • The manipulation of a variable (IV) and the additional controls for confounding variables allow for greater internal validity in experiments that other types of research design
  • Independent variables can be manipulated:
    • By type of something, amount of something, or the presence/absence of something o Between subjects where each participant receives only ONE level of the IV o Within subjects where each participant receives ALL levels of the IV
  • An interaction between IVs can occur such that the effect of one IV depends on which level of the other IV one is looking at.
    • For example: an IV can show a difference between levels for Level 1 of another IV but show no difference between levels for Level 2 of the other IV