D.4 Identify the defining features of single-case experimental designs

Single-case experimental designs (SCEDs) are powerful tools that allow researchers and teachers to evaluate the effectiveness of interventions on individual students. In these designs, one person serves as their own control, meaning their behavior is measured both before and after an intervention to see its effects.

The defining features of single-case experimental designs:

1. Repeated Measures

In SCEDs, a participant’s behavior is measured repeatedly throughout the study. These measurements are taken in both the baseline phase (before the intervention) and after the intervention is applied. This helps ensure that any changes in behavior are due to the intervention, rather than other factors.

Why it matters: Repeated measurements help control for variables that could interfere with the study results, such as changes in the participant's routine or environment.

2. Baseline Data

Before implementing the intervention, data is collected to establish a baseline. This is a "starting point" that shows how the behavior is before any intervention is applied.

Why it matters: Baseline data provides a comparison point, allowing researchers and teachers to see if the intervention leads to significant changes in behavior.

3. Prediction, Verification, and Replication

To ensure that the intervention is effective and the results are valid, researchers use three strategies:

Prediction: Before the intervention, researchers predict what the behavior will look like if nothing changes (i.e., if the intervention isn’t applied). This helps identify whether changes in behavior are truly due to the intervention.

Verification: This is the process of showing that changes in behavior wouldn’t have happened without the intervention. It helps rule out other factors that could have influenced the behavior.

Replication: The intervention is applied repeatedly to confirm that the changes are consistent across different phases of the study. Replication helps ensure that the results are reliable.

Single-case experimental designs provide a clear, personalized way to assess the impact of interventions on a single student. By focusing on one individual, this design helps ensure that the intervention is truly meeting that student's needs. Understanding these features can help parents and teachers make informed decisions about interventions, ensuring they are effective and meaningful for each child.