Board Certified Behavior Analyst (BCBA) Practice Test

What is crucial when using an alternating treatments design?

1. Randomly order treatment conditions in each phase

2. Apply the same treatment to all subjects

3. Document changes after each treatment

4. Use a fixed order of conditions

The correct answer is: Randomly order treatment conditions in each phase

The key aspect of using an alternating treatments design is that the treatment conditions are applied in a manner that minimizes potential confounding variables and allows for a clear comparison of the effects of each intervention. Randomly ordering treatment conditions within each phase helps to control for any order effects that could skew the results. This is important because if one treatment is consistently administered before another, it could influence how effective the subsequent treatment appears to be due to carryover effects or patterns formed during the first treatment. In contrast, a fixed order of conditions may lead to systematic biases where the outcome of later treatments could be affected by prior experiences. Similarly, applying the same treatment to all subjects does not utilize the alternating treatments design, which is specifically meant to compare different interventions. Documenting changes after each treatment, while important for maintaining accurate records, does not address the design's core requirement of treatment sequencing and ordering. Therefore, randomizing the order of treatment conditions is crucial to the integrity and validity of data collected in an alternating treatments design.