Ch. 14: Single-Subject Designs

Question 1

what is needed for single-subjects designs to qualify as experiments

Answer 1

these designs must include manipulation of an independent variable and control of extraneous variables to prevent alternative explanations for the results

Question 2

single-subjects designs

Answer 2

experimental research designs that use the results from a single participant to establish the existence of cause-and-effect relationships

Question 3

how was the single-subjects design developped?

Answer 3

it was developed by behaviourists examining operant conditioning

Question 4

goal of single-subjects designs

Answer 4

to identify cause-and-effect relationships between variables

Question 5

single-subject designs incorporate elements of _____

Answer 5

descriptive case studies and quasi-experimental time-series designs

Question 6

baseline

Answer 6

there is a clear measure of baseline behaviour before administering treatment

Question 7

repeated observations

Answer 7

multiple measures are obtained during baseline and each treatment condition to ensure that outside factors are not influencing behaviour until the researcher intervenes and changes to the next treatment condition

Question 8

what is needed for the success of a single-case design?

Answer 8

the series of observations/measurements during the baseline and each treatment must be stable

Question 9

replication

Answer 9

if results show a clear change in behaviour when the researcher changes the treatment condition, the same change must be demonstrated a second time before the researcher can conclude the change in treatment is responsible for causing the change in behaviour

Question 10

evaluating results from a single-case study

Answer 10

Presentation and interpretation of results from a single-case experiment are based on visual inspection of a simple graph of the data

Question 11

Two reasons for skepticism concerning the results of single-case studies

Answer 11

• There is no control over extraneous variables
• The results may simply be due to chance

Question 12

phase

Answer 12

a series of observations of the same individual under the same conditions

Question 13

baseline observations

Answer 13

the observations made when no treatment is being administered

Question 14

annotation of baseline observations

Answer 14

A series of baseline observations is called a baseline phase and is identified with the letter A

Question 15

treatment obseravtions

Answer 15

the observations made when treatment is being administered

Question 16

annotation of treatment observations

Answer 16

• A series of treatment observations is called a treatment phase and is identified by the letter B
• When a study contains two or more distinct treatments, B identifies the first treatment condition, and C, D, and so on identify other treatments
• When a study contains modifications of the basic treatment B, the different modifications are called B₁, B₂, etc.

Question 17

level

Answer 17

the magnitude of the participant’s response

Question 18

trend

Answer 18

a consistent increase or decrease in the magnitude of behaviour across the series of observations that make up the phase

Question 19

stability

Answer 19

the degree to which the observations show a pattern of consistent level or consistent trend

Question 20

can stable data show variations?

Answer 20

Stable data may show minor variations from a perfectly consistent pattern but the variations should be relatively small and the linear pattern clear

Question 21

dealing with unstable data

Answer 21

• Keep making observations and hope that the data will stabilize and reveal a clear pattern
• Average a set of two or more observations
• Look for patterns within the inconsistency

Question 22

length of phases

Answer 22

• To establish a pattern, a phase must consist of a minimum of three observations
• Typically, 5-6 observations are necessary to determine a clear pattern
• When high variability exists, you should make additional observations

Question 23

phase change

Answer 23

involves changing the conditions, usually by administering or stopping a treatment

Question 24

goal of a phase change

Answer 24

to demonstrate that adding or removing a treatment produces a noticeable change in behaviour

Question 25

when is a phase change not appropriate?

Answer 25

- When data in a baseline phase show a trend indicating improvement, - This can result in ambiguous results

Question 26

when does the researcher have an obligation to begin the treatment?

Answer 26

- If the baseline data indicate a high level of dangerous or threatening behaviour - If the behaviour is brought under control during a treatment phase, the researcher can consider resuming the experiment by changing back to a baseline phase

Question 27

when should a researcher stop or modify the treatment?

Answer 27

If a treatment appears to produce an immediate and severe deterioration in behaviour, the researcher/clinician should stop, change, or modify the treatment immediately

Question 28

appropriate vs. necessary phase changes

Answer 28

- If the responses establish a clear pattern, a change is appropriate - If the responses indicate a serious problem, a change is necessary

Question 29

4 visual inspection techniques

Answer 29

- change in average level - immediate change in level - change in trend - latency change

Question 30

change in the average level

Answer 30

involves comparing the average levels of behaviour between phases

Question 31

immediate change in level

Answer 31

involves comparing the last data point in one phase with the first data point in the following phase

Question 32

change in trend

Answer 32

involves assessing whether the trend observed in one phase is noticeably different from the trend in the previous phase

Question 33

latency of change

Answer 33

involves assessing whether the data show a large, immediate change in pattern

Question 34

what is the most convincing evidence for a difference between phases?

Answer 34

latency of change

Question 35

reversal design

Answer 35

consists of a series of phases, including baseline phases followed by a treatment phase and at least one replication of a baseline followed by a treatment

Question 36

what is the most commonly used reversal design?

Answer 36

ABAB design

Question 37

ABAB design

Answer 37

consists of a baseline, treatment, return to baseline, and second treatment phase

Question 38

goal of the ABAB design

Answer 38

to demonstrate that the treatment causes changes in the participant’s behaviour by showing that: 1. The pattern of behaviour in each treatment phase is different from the pattern in each baseline phase 2. The changes in behaviour from baseline to treatment and from treatment to baseline are the same for each of the phase-change points in the experiment

Question 39

limitations of the ABAB design

Answer 39

- Its credibility depends largely on the reversal (return to baseline) - Withdrawing treatment may not result in a change in behaviour - This means that it is not appropriate to evaluate treatments that are expected to have a permanent or long-lasting effect - The ethical question of withdrawing a successful treatment

Question 40

variations on the ABAB design

Answer 40

- The exact sequence of baseline and treatment phases often evolves during the study, creating an unlimited number of potential designs - Not every potential phase sequence qualifies as an experimental design - To qualify as an experiment, a study must consider alternatives and eventually produce one unambiguous explanation for the results

Question 41

multiple-baseline design

Answer 41

begins with two simultaneous baseline phases. A treatment phase is initiated for one of the baselines while baseline observations continue for the other. At a later time, the treatment is initiated for the second baseline

Question 42

multiple-baseline across subjects

Answer 42

when the initial baseline phases correspond to the same behaviour for two separate participants

Question 43

multiple-baseline across behaviours

Answer 43

when the initial baseline phases correspond to two separate behaviours for the same participant

Question 44

multiple-baseline across situations

Answer 44

when the initial baseline phases correspond to the same behaviour in two separate situations

Question 45

component-analysis design

Answer 45

consists of a series of phases in which each phase adds or subtracts one component of a complex treatment to determine how each component contributes to the overall treatment effectiveness

Question 46

Two main strategies for conducting a component-analysis design

Answer 46

- Component analysis with a reversal design - Component analysis with a multiple-baseline design

Question 47

component analysis with a reversal design

Answer 47

Involves a return to baseline followed by a second demonstrating the treatment effect

Question 48

phases of the component analysis with a reverse design

Answer 48

1. Baseline phase 2. A series of phases adding treatment components one by one 3. Return to a baseline phase 4. Repeat the series of phases adding treatment components

Question 49

variations on the component analysis with a reversal design

Answer 49

It is also possible for it to add one component, return to baseline, add a different component, and then return to baseline

Question 50

component analysis with a multiple-baseline design

Answer 50

Replicates the demonstration of a treatment effect by repeating the effect for a different participant (or behaviour or situation) at a different time

Question 51

goal of the multiple-baseline design

Answer 51

to show that the treatment causes a change in behaviour

Question 52

criteria for a successful multiple-baseline design

Answer 52

- There is a clear and immediate change in the pattern of behaviour when the researcher switches from a baseline to a treatment phase - The design includes at least two demonstrations that behaviour changes when the treatment is introduced

Question 53

strength of the multiple-baseline design

Answer 53

It eliminates the need for a reversal or return-to-baseline phase, making it well-suited for evaluating treatment effects that are permanent or long-lasting

Question 54

weaknesses of the multiple baseline design

Answer 54

- It can be difficult to identify similar but independent behaviour - The clarity of the results can be compromised by individual differences between participants or behaviours