Single-subject Experimental Research Unit 7

Question 1

What does single-subject design focus on?

Answer 1

Examines behavior change in ONE person

Question 2

Advantages of single-subject?

Answer 2

• Allows for intensive study of the individual
• It requires only a small number of subjects, where some experimental subjects are hard to find (brain damage) this might be the only feasible design
• withholding a potentially beneficial treatment is not necessary

Question 3

Most basic single-subject design is ABA design

Answer 3

ABA is also called reversal design

A - level of a behavior is established (subject’s behavior of performance before introducing experimental condition) (WITHOUT TREATMENT)

ex) have client keep a food diary of what they eat, before their meal plans are changed to see what their baseline is

B - is introduced and maintained while performance is measured (WITH TREATMENT)

A - final phase involves returning to the A condition (baseline phase) (WITHOUT TREATMENT AGAIN)

Question 4

Single-subject has internal validity

Answer 4

1. each participant uses themselves as the experimental control, as the baseline serves as the reference point against which to compare data during research
2. considering the behavior is reversible following the withdrawal of the experimental condition rules out the possibility that changes in baseline are caused by extraneous variables

Question 5

Extension of ABA design is the ABAB (+ advantage)

Answer 5

Same as ABA - except with treatment repeated after the withdrawal (A) phase

Advantage over ABA is participant will end up in the experimental condition

Question 6

When ABA and ABAB are inappropriate (irreversible) which design is used?

Answer 6

Multiple baseline designs

Question 7

What are the 3 types of multiple baseline designs?

Answer 7

1. Across subjects
2. Across behaviors
3. Across settings

Question 8

Disadvantages of single-subject design?

Answer 8

1 - some effects are small relative to the amount of variability in the experiment
2 - some experimental effects are between-subject effects (impossible for a participant to receive 2 opposite sets of instruction in experiment)

Question 9

When is ABAB design superior to ABA?

Answer 9

When one wishes to continue the beneficial treatment (B)

Question 10

2 problems with ABA

Answer 10

1. the effect of manipulation may not be reversible

2. you may want to leave participants in the new condition rather than return them to their old states