Chapter 14:Single Subject Designs

Question 1

What are the three crucial elements of a single subject design?

Answer 1

• Start to measure someone at baseline for control
• repeated observations
• replication

Question 2

Difference between consistent level VS consistent trend?

Answer 2

Consistent level→ series of measurement with nearly same magnitude
- graphed date points cluster around horizontal line

Consistent trend→ Same difference from one measurement to the next and same direction
- sloping line in graph

Question 3

How to deal with unstable data?

Answer 3

• Wait until the data stabilize→ might take time to see a trend
• Average a set of two or more observations
• Look for patterns within the inconsistency→ ex: weekend might explain the instability

Question 4

How many observations are needed to establish a clear pattern?

Answer 4

5 or6

Question 5

What are the ethical consideration when changing phases in a single subject design?

Answer 5

• If they are improving without treatment→ don’t implement the treatment
• If they are deteriorating quickly, implement the treatment right away
• If the treatment produces severe deterioration, cease or modify treatment immediately

Question 6

What are the limitations of a ABAB design?

Answer 6

• cannot go back/ permanently changed→ ex: treatment is class of meditation
• may result in a slight change but don’t return to baseline
• ethical problem→ if treatment is working for participants

Question 7

WHat are the three types of multiple baseline designs?

Answer 7

Multiple-baseline across subjects
- Begin with two simultaneous baseline phases
- treatment phase are not initiated at the same time

Multiple-baseline across behaviors
- initial baseline phases correspond to two separate behaviors for the same participant.

Multiple-baseline across situations
- initial baseline phases correspond to the same behavior in two separate situations
- ex: biking in day VS biking at night instructions not given at same time

Question 8

What are the strengths and weaknesses of a multiple baseline design?

Answer 8

Strengths
No return to baseline needed
Good for long-lasting treatments

Weaknesses
It can be difficult to identify similar but independent behaviors
Results can be compromised by individual differences between participants or between behaviors.

Question 9

What is a component analysis design?

Answer 9

Consist of a series of phases→ Each phase adds or subtracts one component of a complex treatment
- determine how each component contributes to overall treatment effectiveness
- can either start with baseline and add component one by one OR start with full treatment phase and remove component one by one

Question 10

What are the strength of a single subject design?

Answer 10

Allows researchers to establish cause-and-effect relationship with one participant or subject
Flexibility: the researcher is free to modify the treatment or change to a new treatment if a participant or subject fails to respond to treatment
No need to standardize treatment across groups—a single participant or subject is used
- tailor to the participant’s needs

Question 11

What are the weaknesses of a single subject design?

Answer 11

Relationship among variables is for only one participant or subject
- May threaten external validity (generalization)
Multiple, continuous observations are required
- difficult if person has to come to a lab for that
Absence of statistical controls
- Reliance on graphs to display data
- there is some statistical significance tests that can be used