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13 terms

Psych 12 Final (Quasi-Experimental Designs)

Key features about Quasi-experiment
-no manipulation of IV
-no random assignment
-lower internal validity
One-shot case study
measure DV for one group; no manipulation of IV, no comparison group
One-group pretest-posttest design
measure the DV prior to event or intervention, measure after. Only one level of IV, no comparison group
Disadvantages of one group pretest-posttest design
-maturation: people might change over time
-pretest sensitization: people might change because simply taking pretest prompted change
-history: something might occur in the world that prompts people to change
Non-equivalent groups designs
participants are assigned to groups by means other than randomization
-usually find similar group as a control group
Nonequivalent grous posttest-only designs
only look at posttest
Nonequivalent groups pretest-posttest designs
look at post and pretest
Interrupted time series designs
measure DV several times before and after treatment
Single interrupted time series
group 1(only group) - OOOXOOO
-introduction of gun control law in one state
Interrupted time series with reversal
group 1(only group) - OOOXOOO(-X)OOO
-intro and removal of gun law in one state
Control group interrupted time series
group 1 - OOOXOOO
group 2 - OOO-OOO
-comparison of one state with new gun law and one state without new gun law
Longitudinal designs
-follow groups of people over time (O O O O O O)
-Quasi-IV is time
-advantages and disadvantages hard to find AND keep Ps
-compare with cross-sectional designs
Generational effects
-advantage of longitudinal study - controls generational effect
-different generation, different opinions