Board Certified Behavior Analyst (BCBA) Practice Test

What does a clear change in the level between baseline and intervention phases of a graph typically indicate?

1. No impact of the intervention on behavior

2. An increase in variability of responses

3. A significant effect of the intervention on behavior

4. Unchanged participant performance over time

The correct answer is: A significant effect of the intervention on behavior

A clear change in the level between baseline and intervention phases of a graph typically indicates a significant effect of the intervention on behavior. This is because a marked change in behavior as reflected in the data visually represents that the intervention has had a measurable impact. In applied behavior analysis, when you chart data across different phases, such as baseline (where no intervention is applied) and intervention (where a specific treatment or strategy is being implemented), a sudden shift in the data level signifies that something in the environment—specifically the intervention—has influenced the behavior being observed. This change demonstrates the effectiveness of the intervention being tested and suggests that the factors inherent in the intervention are likely responsible for the behavioral change. This helps practitioners make informed decisions about the continued application or adjustment of the intervention strategies to achieve the desired outcomes in behavior modification. Undoubtedly, spotting such changes in level within graphical data is a fundamental component of interpreting behavior analysis data, as it provides compelling evidence of an intervention's success.