PSYC 270 Exam 2, Part 3

  1. Advantages of Between-Subjects Designs
    Includes a control or comparison group that helps to control for many extraneous variables.

    Can randomly assign participants to groups, which helps to balance extraneous variables across the groups.
  2. Disadvantages of Between-Subjects Designs
    You can’t always randomly assign participants to groups.

    Large individual differences between participants may make it difficult to observe meaningful group differences.
  3. If the subjects are used more than once or matched, this design is called a
    Within-Subjects Design
  4. Advantages of Within-Subjects Design
    They take fewer participants.

    They typically have more statistical power (such as a matched t-test)
  5. Disadvantages of Within-Subjects Design
    You have to worry about practice effects and carryover effects
  6. equalizing the amount of practice, for example, you could test one person in the B1, B2, B3 order, another with B1, B3, B2, until every order is tested; used to avoid practice and carryover effects
  7. a factorial design in which there is at least one between-subjects factor and at least one within-subjects design
    mixed design
  8. Mixed Designs are useful when:
    You might end up testing the subjects too much in a wholly within-subjects design
  9. total variance=
    systematic + nonsystematic variance
  10. "between group" variance; experimental variance due to the IV; due to confounding variables
    systematic variance
  11. error variance or variance within the groups; due to chance factors
    nonsystematic variance
  12. If between-group variation is not significantly ______ than within-group variance, then group differences probably do not contribute anything beyond chance variability
  13. statistical anaylsis comparing more than 2 sets of scores
  14. Sources of sequence/carryover effects
    learning, fatigue, habituation, sensitization, contrast, adaptation
  15. ways to deal with carryover effect
    random order; counterbalancing
  16. advantages of matched design
    can control for subject variables that may otherwise obscure the effect of the IV
  17. disadvantages of matched design
    matching variable needs to be reliable, difficult finding enough participants who are matched, impossible to match on every possible variable that might influence the IV
  18. when greater than 2 IV, we can examine _______ and ______
    main effects; interactions
  19. overall effect of one IV (ignoring the other)
    main effect
  20. effect of one IV depends on the level of a second IV
    interaction effect
Card Set
PSYC 270 Exam 2, Part 3
research methods