The researcher is using a "multiple-baseline-across-settings" design.
The multiple baseline design is valuable for intercessions that are irreversible because of learning impacts, and when treatment can't be pulled back. In this plan, behavior is estimated crosswise over either multiple individuals, behaviors, or settings.
For the multiple-baseline-across-behaviors design, various practices of a similar individual are considered. In the settings design, a person's conduct is examined over various settings and circumstances. Finally, in the multiple-baseline-across-subjects design, a similar conduct is considered for different people.