Ch. 11 Flashcards
Not- Quite Experimental Designs
Classic Experimental Design
—— participant are randomly assigned to IV conditions
——IV is manipulated
——DV is measured
What if you can’t randomly assign?
—–Signle-Case Designs
——Quasi-experimental designs
——–Developmental designs
Single- Case Experimental Designs
- A.K.A single subject designs or small N designs
- Use this when trying to figure out whether an experimental manipulation had an effect on single participant
- basically, you record the baseline control) behavior, than record behavior during the treatment period, to see if it changed
- problem is there are many alternative explanations for why the behavior chaged
Single-Case Experimental Designs: Reversal Designs
- record the baseline behavior, then record behavior during the treatment period, then remove to treatment to record a second baseline period
- called ABA design, or withdrawal design
- to rule out possibility that some unrelated event caused the change in behavior, you can do multiple reversals ABA design or ABA BAB design)
Single- Case Experiments: Multiple Baseline Designs
- sometimes its unethical or impossible to reverse El treatment
0n this case, you can take multiple baseline measures at diff times, and
multiple post-treatment measures at different times- The multiple baselines can be across subjects, introducing the IV manipulation at different points in time
- across=behaviors
- across situations
- interrupted timer series design
- control series design
—– try to find a comparison group, to act like a control group
Developmental Research Designs
Cross- Sectional Method
- study people of different areas of a single point in time
— Longitudinal Method
—– study the same group of people at different points in time as they grow older
COMPARISON of LONGITINAL And CROSS-SECTIONAL METHODS
- advantages of cross- sectional designs:
—— much faster and cheaper - disadvantages of cross–sectional designs
—— differences may be due to the cohort effects, not age-related change - advantages of longitudinal designs
——– can actually see how a variable changes in each person, and the group, as they age - disadvantages of longitudinal designs
——— expensivee difficult and takes many years
———- attraction can impact results
SEQUENTIAL METHOD
- do a cross- sectional study and longitudinal study at the same time
Single Case Experiments: Replications
replication= do the same single -subject experiment with additional subjects
- enhances generability, and helps rule out individual differences as casual factors
QUASI- EXPERIMENTAL DESIGNS
- you use these when you want to study the effect of an independent variable, but you aren’t able to exercise experimental control over it
— limits ability to make definitive statement about cause and effect
Quasi experimental design- One Group Post Test only design
- you have nothing to compare it too
Quasi-experimental - Nonequivalent control group pretest-post test design
-concern is that there’s section differences between groups
Quasi Experimental Design- One Group pretest post test design
- a change in one group pretest–post test design can’t rule out alternative explanations
Quasi- experimental Design; Nonequivalent control group design
- does have control group
- participants not randomly assigned
- concern is that there’s selection differences between groups
Quasi experimental design- -nonequivalent control group pretest- post test design
—- can use pretest- to see if groups were the same before start of experiment
—- can also look at look at change in scores from pretest to post test
Quasi experimental Design- Propensity score matching of nonequivalent treatment and control groups;
—- similar to matched pairs Design; measure all participants health scores match each person in experimental group with someone in control group with similar score
- Propensity score matching is statistically matching the groups on multiple variables instead of just one