Module 6 - Studying the Single-Case

Single-Case Designs

Different types of research designs when compared to your group designs

If and when they acquire a skill

What is nice to see in single-subject case designs nice?

Where the data is plotted

What do the blue dots on an AB design show?

Percentages / scores

What does the y-axis represent on the graph?

Number of observations

What does the x-axis represent on the graph?

3

How many baseline data points should be taken?

Match

Should the treatment, observation data points be matched, less than, or more than the baseline data points?

Maturation effect

Natural biological, psychological, or behavioral changes within individuals over time that can influence study outcomes

Ethical Issues

What issue occurs when one condition gets the intervention and the other (control) doesn’t?

Practical Issues

What issue occurs when you can’t randomly assign students into treatment and control classrooms?

Statistical Issues

What issue occurs when you are taking the group average that will result in information loss?

Generality Issues

What issue occurs when you aren’t always able to generalize group data to an individual since that individual is different in some way from the group

Intersubject Variability Issues

What issue occurs when some participants improve while others don’t?

The process of skill acquisition

What do single-case methods allow researchers to understand?

Conclusions

In a single-case method, what is tentative and subject to replication studies?

Data

What is numerical and collected objectively?

• Multiple sources of information

• Interobserver agreement

What are things that reliability and validity determined through?

Independent

In single-case methods, what variable is manipulated and controlled ?

Qualitative design

Are simple case studies more of a qualitative or quantitative design?

Quantitative design

Are single case time series designs more of a qualitative or quantitative design?

Simple Case Studies

Which single case method is more of a qualitative design?

Single Case Studies

This is where you use a lot of words to describe a single case, but it is not a numerical type of analysis

Single case time series design

Which single case method is more of a quantitative design?

Single case time series design

You are looking to have a single case that is followed across time with data collection across time and there is a baseline phase about how the performance is before the intervention started and data is also collected in a second type of phase after the intervention has been introduced

Generate ideas

Simple case studies are an excellent choice when the study intends to do what?

Time-series

Repeated measurement of one or more intact groups (pretest-intervention-posttest-posttest)

Quasi-experimental design

Are single case time series design more of a true experimental or quasi-experimental design?

Draw inferences about the effectiveness of the intervention

When you look for patterns of data across conditions, what do you hope to do?

Pretreatment phase

What is the baseline phase also called?

• Data on the extend of the subject’s problem in the natural setting and the status of the behavior of interest

• A predictor of the subject’s behavior if the intervention fails

What is the baseline phase provide?

• Maturation effect

• Statistical regression

• History effect

Why would the baseline not be stable causing the DV to fluctuate?

Baseline condition

What does A represent in an A-B Design?

Experimental condition (treatment)

What does B represent in an A-B Design?

Withdrawal studies

This study is intended to show you that there is some sort of change as a response to the independent variable being removed

A-B Design

• Single subject is observed under the baseline condition (until the dependent variable is stabilized)

• Treatment is then introduced

• The dependent variable is measured the same number of times as the baseline while the intervention is occurring

• Simplest and weakest design

• Highly susceptible to threats to internal validity (e.g., history, maturation)

Baseline phase where the observations of the dependent variable are taken in the natural setting

What does A1 mean in the A-B-A Design?

Intervention (data collected) where IV Is introduced

What does B stand for in the A-B-A designs?

Second baseline phase where the observation of the DV are taken after the withdrawal of the intervention

What does A2 stand for in the A-B-A designs?

Dependent

Between the independent and dependent variable, what do we want to be high?

Reintroduction of the intervention

What does B2 mean in an A-B-A-B design?

A more causal relationship

What does the second B allow you to make?

First treatment

What does B stand for in the A-B-A-C design?

Second treatment

What does the C represent in the A-B-A-C design?

1 independent variable

A-B-A designs typically investigate WHAT?

Counterbalancing

What gives you a lot more control and gives you an ability to argue that multiple treatment interference wasn’t a big deal in your study

Direct Replication

Use additional participants who present similar behaviors as those in the original study where the replication needs to be as similar as possible

Systematic Replication

• Varying certain parameters of the original study (e.g., treatment setting, clinician, types of disorders, ages)

• The more replication studies of this nature, the more confidently the researcher can generality of results when compared to direct replication studies

Effective

If the original study and the replicated study show the same treatment effect, what does the researcher may suggest?

Visual Inspection

Easy to visually inspect graphs and get an idea of there is any change

Subjective Analysis

If 2 separate people were to look at it, we may not all agree on all the senses

Poor

Does visual inspection have good or poor interrupter agreement ?

Combined Approach

What is the recommended approach when determining the effectiveness of intervention?

• Smaller number of participants who act as their own controls

• Avoids problems with matching – not looking for initial group equivalency

• Examines behavior of the individual over time and getting acquisition data

• Flexible design that can be modified during the study

• Intraparticipant variation can be measured and controlled

What are some advantages of single case designs?

• Lessened ability to generalize results (than group designs)

• Greater need for replications

• Interparticipant variability is hard to account for

• Need more time and effort per participant to collect measurements

• Attrition can seriously affect results

What are some disadvantages of single case designs?

Acquisition data

Learning about how that individual responds to that intervention over time

Withdrawal designs

What are not appropriate if you are taught a skill?

Changing-Baseline Design

What is a multiple-baseline design also called?

Multiple-Baseline Designs

Series of A-B designs stacked on each other that involves more than one subject, behavior, or situation

The intervention that caused the change

What do multiple baseline designs allow you to argue?

• History effect

• Maturation effect

• Statistical regression

With multiple baseline designs, what can we argue that there is none of?

Dependent

Are subjects in multiple-baseline designs independent or dependent of each other?

• Not able to withdraw the independent variable to demonstrate its controlling effect on the dependent variable

• Require a lot of data collection and organization

• Needs to occur over a longer period of time

• Requires more resources for planning, implementing, and insuring cooperation

• Morality/attrition can be problematic (if you are only studying one individual)

What are weaker designs in ABA?