Chapter 3 - Single-Subject Research Designs to Evaluate Interventions

Question 1

Dependent variable

Answer 1

The behaviour of the subject

Question 2

Independent variable

Answer 2

The treatment or intervention

Question 3

The Reversible-Replication (ABAB) Research Design has 4 phases:

Answer 3

a baseline phase, a treatment phase, a reversal to baseline phase & a replication of treatment phase

1) The practice performance of each subject was 1st studied during a baseline phase -sessions conducted during which performance was monitored without the intervention
2) Each subject was introduced to as treatment phase in which they utilized the self-monitoring plus feedback package
3) To assess whether or not the improvement was due to treatment, a reversal to baseline phase was conducted in which treatment was withdrawn
4) To further assess the effects of treatment, a replication phase was conducted in which the treatment was again applied to each of the skaters

Question 4

A finding is said to have internal validity if the…

Answer 4

independent variable did, in fact, cause the observed changes in the dependent variable

Question 5

5 commonly used guidelines for visually inspecting data to determine whether a treatment has had a consistent effort:

Answer 5

• 1st, the last few data points of the baseline should be reasonably STABLE or in a direction opposite to that predicted for the effects of treatment
• 2nd, one has greater confidence that an effect has been observed the more times it is REPLICATED
• 3rd, one has greater confidence that an effect has been observed when there are few OVERLAPPING data points b/t adjacent baseline & treatment plans

4th, one has greater confidence that an effect has been observed the SOONER the EFFECT is OBSERVED following the intro of the treatment

Final, one has greater confidence that an effect has been observed if the EFFECT is LARGE

Question 6

A limitation of the reversal replication design is:

Answer 6

that it may be undesirable or impossible to obtain a reversal

Question 7

A Multiple-Baseline Design Across People

Answer 7

With this design, baseline data was taken concurrently across all subjects

Then the intervention was introduced to the 1st subject while the other subjects remained on baseline

Then, in a staggered fashion across the remaining subjects, the intervention was introduced

Question 8

A finding is said to be externally valid to the extent that it can…

Answer 8

be generalized to other behaviours, individuals, settings, or treatments

Question 9

A potential research limitation of the multiple-baseline design across people is that…

Answer 9

the 1st subject might explain the treatment or model the desirable behaviour to the other subjects, causing them to impure in the absence of treatment
- Also, it is not always possible to find 2 or more subjects, nor the additional observes to gather the necessary data

Question 10

A Multiple-Baseline Design Across Behaviours

Answer 10

1st, the behaviours are observed in baseline sections

Then, a treatment is introduced to the 1st behaviour & its effects are examined while the other behaviours remain on baseline

Then the treatment is introduced to the 2nd behaviour & its effects are examined, & so on for all of the observed behaviours

Question 11

A Multiple-Baseline Design Across Situations

Answer 11

• 1st, a behaviour of an individual is baseline din 2 or more situations

Then, in a staggered fashion, the treatment is introduced to the behaviour of that individual in the 1st situation & the effects are assessed while the behavior remains on baseline in the 2nd (& other situations

Then the treatment is introduced to the behaviour in the 2nd situation, & so on

Question 12

A potential research limitation is that when the treatment is applied to the behaviour…

Answer 12

in this 1st situation or setting, it may cause subsequent improvement in all settings
- When this happens, the experimenter is not able to conclude that the improvement was necessarily a result of the treatment

• Other potential limitations are that the behaviour may occur in only one setting, or there may not be sufficient observers to gather the necessary data

Question 13

Alternating-Treatments for Multi-Element Design

Answer 13

The preceding research designs are ideally suited for demonstrating that a particular treatment was indeed responsible for a specific behavioural change

• This design involves measuring a behaviour as it occurs during 2 or more alternating treatments. One treatment per session is typically applied, & treatments are alternated across session

Question 14

Alternating-Treatments for Multi-Element Design has advan. over the reversal replication & multiple-baseline designs:

Answer 14

1) Allows for the comparison of the effects of treatments within an individual over time & is ideally suited to detect delayed treatment effects b/c it can include an ongoing baseline as one of the conditions for comparison
2) When an ongoing baseline is one of the conditions, the design is able to be used ñ behaviour (such as athletic performances) that occur at unstable rates
3) B/c all conditions can be introduced concurrently, it avoids the need for lengthy baseline or treatment conditions that commonly occur at reversal replication designs
4) The design also makes it possible to terminate less effective treatments early bk the effects of different treatments can be detected quickly

Question 15

2 limitations to the alternating-treatments design:

Answer 15

1) Generalization may occur b/c of similarities between the conditions
2) Contrasting effects may enhance differences between the alternating-treatment conditions

Question 16

2 possible solutions to these problems from the alternating-treatments design:

Answer 16

1) It would be possible to observe the behaviour during several baseline sessions prior to the introduction of the alternating treatments
2) Conduct a few additional sessions with just the most effective treatment at the end of the study

Question 17

Characteristics of Single-Subject Designs

Answer 17

Single-subject designs include:

• the reversal-replication design
• multiple-baseline designs
• & the alternating treatments design

Typically include 3 to 5 subjects

Question 18

Single-subject designs typically include 5 characteristics:

Answer 18

1. They typically include INTEROBSERVER RELIABILITY (IOR) assessment of the dependent variable to ensure that the records of the athlete’s behaviour are accurate
2. Steps are typically taken to ensure that the treatment was applied as intended & as described, which is referred to as ASSESSMENT OF TREATMENT INTEGRITY or a PROCEDURAL RELIABILITY ASSESSMENT
3. They typically require REPEATED measurement OF the main DEPENDENT variable throughout the duration of the study, as opposed to pre/post assessments
4. Single-subject designs do NOT typically include CONTROL GROUPS. Instead, all subjects are studied under all conditions of the experiments
5. Researchers who use single-subject designs typically RELY ON VISUAL INSPECTION of data to assess the effects of treatment

Question 19

When inspecting one’s data to judge whether or not the treatment has an effecto on the dependent variable, the researcher has greater confidence that an effect has been observed:

Answer 19

a) when baseline performance is stable or in a direction opposite to that observed for the effects of treatment:
b) the greater the # of times that an effect is replicated both within & across subjects;
c) the fewer the overlapping data points b/t baseline & treatment phases;
d) the sooner the effect is observed following the introduction of treatment; &
e) the larger the effect is comparison to baseline

Question 20

Single-Subject vs. Group Research Designs

Answer 20

There are 3 commonalities b/t single-subject & group research designs

• Both approaches typically have the goal of evaluating the effects of an independent variable on a dependent variable
• Both require acceptable inter-observer reliability assessments of the dependent variable
• Both typically require acceptable procedural reliability assessments

Question 21

There are 3 commonalities b/t single-subject & group research designs:

Answer 21

1. Both approaches typically have the goal of evaluating the effects of an independent variable on a dependent variable
2. Both require acceptable inter-observer reliability assessments of the dependent variable
3. Both typically require acceptable procedural reliability assessments

Question 22

There are 3 characterisitcs that differentiate single-subject designs from control-group methology:

Answer 22

1. Single-subject designs typically require repeated measurement of the dependent variable throughout the duration of the study, as opposed to pre/post assessments that are common with control-group studies
2. Single-subject designs do not typically include control groups
   - Instead, all subjects are studied under all conditions of the experiment
3. Single-subject researchers typically rely on visual inspection of data to judge whether a treatment had an effect on a dependent variable, as opposed to looking for a statistically-significant difference b/t the average performance of the control group & the experimental group

Question 23

There are 3 limitations of control-group research for behavioural sport psychology:

Answer 23

1. It is often difficult to locate enough subjects with the same performance problem to form the different groups
2. Coaches & athletes may resist participating in a no-treatment control group
3. B/c control group designs focus on the average performance of groups as they exist at a particular point in time, control-group researchers typically use pre/post assessments rather than continuous monitoring of individual athletes across several practices &/or games

Question 24

User Friendly Features of Single-Subject Designs

Answer 24

They require only a small # of subjects to demonstrate internal validity (& sometimes, external validity) of treatments, athletic performance is monitored continuously across practices or competitions, & all subjects are typically exposed to both baseline & treatment conditions

In a review of 40 years of research, 78 studies were identified that used single-subject designs in sport psychology