Show:
A-B
A-B-A
A-B-A-B
Multiple baseline
100
What are the A and B phases?
A: Repeated measures of dependent variable under non-treatment conditions B: Repeated measures of dependent variable under treatment conditions (independent variable)
100
What happens during the 2nd A phase?
Cease manipulating independent variable Withdraw treatment
100
T/F: You are introducing a completely new treatment during the 2nd B phase.
False!
100
What are the characteristics of multiple baseline?
1. Establish 2 or more baselines 2. Coordinate phase changes across each baseline at different points in time 3. Coordinate phase changes across each baseline after a change in level or trend has been observed on each of the baselines
200
What does the A phase examine? (3 things!)
Trend, level and variability
200
What are 3 possible outcomes of the withdrawal phase?
Deteriorating, Continued improvement, No change
200
What are the threats to internal validity?
NONE! (I think?) Satisfying logic of design account for threats to internal validity Demonstrating experimental control and replicating first AB phase control for alternative explanations
200
What can you establish baselines across?
Behaviors, Settings, Persons
300
What are 3 possible treatment outcomes of phase change?
Improvement, Deterioration, No improvement
300
What are possible threats to internal validity of this design?
NONE! (I think?) Satisfying logic of design account for threats to internal validity Demonstrating experimental control accounts for alternative explanations
300
When can you move onto the 2nd A phase?
If a clear change emerges.
300
How does it control for treats to internal validity?
Multiple baseline replicates phase changes on more than one baseline Subsequent baseline is control for each earlier baseline Baseline 2 is control for Baseline 1 Baseline 3 is control for baselines 2 and 1
400
What are possible treats to internal validity of A-B design?
History, Maturation, Testing, Statistical regression
400
What might be unethical about this design?
Withdrawing treatment from an individual who needs it.
400
When can you move onto the 2nd B phase?
If the change reverts to baseline
400
How many baselines are needed?
2 is minimum, 3 is powerful
500
What is A-B design often referred to as?
Quasi-experimental OR case study design
500
T/F: Duration of treatment withdrawal can be relatively short if immediate deterioration is evident
True!
500
What is a great clinical/ethical consideration for this design?
Does not require withdrawal of treatment! YAY!