Single-case research designs: Methods for clinical and applied settings.

Full Answer Section

  The major features of the multiple-baseline design are:

• Multiple behaviors or individuals: The design involves collecting baseline data on multiple behaviors or individuals. This allows the researcher to control for extraneous factors, such as history and maturation.
• Sequential introduction of the intervention: The intervention is introduced to one behavior or individual at a time. This allows the researcher to see the effects of the intervention on each behavior or individual separately.
• Baseline stability: The baseline data should be stable before the intervention is introduced. This ensures that any changes in the target behavior after the intervention is introduced are due to the intervention and not to other factors.

The multiple-baseline design is conducted in the following steps:

1. Identify the target behavior.
2. Collect baseline data on the target behavior for multiple behaviors or individuals.
3. Introduce the intervention to one behavior or individual.
4. Continue to collect data on the target behavior for the other behaviors or individuals.
5. If the intervention is effective, then the target behavior should change after the intervention is introduced.

2. Controlling Threats to Internal Validity The multiple-baseline design controls threats to internal validity that are characterized by the extraneous factors of history and maturation. History refers to events that occur during the course of the study that could influence the target behavior. Maturation refers to changes in the target behavior that are due to the passage of time. The multiple-baseline design controls for history by introducing the intervention to different behaviors or individuals at different times. This means that any changes in the target behavior that occur after the intervention is introduced are unlikely to be due to history. The multiple-baseline design also controls for maturation by collecting baseline data on the target behavior for multiple behaviors or individuals. This allows the researcher to see if there are any changes in the target behavior over time that are not due to the intervention. 3. Variations of the Multiple-Baseline Design Kazdin (1982) describes five variations of the multiple-baseline design:

• Multiple-baseline across behaviors: This is the most common variation of the multiple-baseline design. It involves collecting baseline data on multiple behaviors and then introducing the intervention to one behavior at a time.
• Multiple-baseline across settings: This variation of the design involves collecting baseline data on the target behavior in multiple settings and then introducing the intervention to one setting at a time.
• Multiple-baseline across subjects: This variation of the design involves collecting baseline data on the target behavior for multiple individuals and then introducing the intervention to one individual at a time.
• Multiple-probe design: This variation of the design involves collecting baseline data on the target behavior at multiple times. The intervention is then introduced and the data is collected again at multiple times.
• Changing-criterion design: This variation of the design involves setting a criterion for the target behavior and then introducing the intervention. The criterion is then changed gradually until the target behavior is at a desired level.

Examples of the Multiple-Baseline Design The multiple-baseline design has been used to evaluate the effects of interventions in a variety of settings, including schools, clinics, and hospitals. For example, Kazdin (1982) used the multiple-baseline design to evaluate the effects of a behavioral intervention for a child with autism. The child was having difficulty with social interactions and communication. The intervention involved teaching the child how to use social skills and how to communicate more effectively. The baseline data showed that the child was not engaging in social interactions or communicating effectively. The intervention was then introduced and the data showed that the child's behavior improved. The child began to engage in more social interactions and to communicate more effectively. The multiple-baseline design is a powerful tool for evaluating the effects of interventions. It is a relatively simple design that can be used in a variety of settings. The multiple-baseline design has been used to evaluate the effects of interventions for a variety of problems, including autism, attention deficit hyperactivity disorder, and substance abuse.

Sample Solution

  Multiple-Baseline Design The multiple-baseline design is a single-subject research design that is used to evaluate the effects of an intervention. The design involves collecting baseline data on the target behavior for multiple behaviors or individuals. The intervention is then introduced to one behavior or individual at a time, while the others remain in baseline. If the intervention is effective, then the target behavior should change after the intervention is introduced.