How do N = 1 designs exert control?

N = 1 designs, or single-case designs, are used to measure changes in behavior over time, either through baseline and intervention periods or by manipulating different conditions in a single subject. These designs are used to exert control over a particular variable—usually behavior—by obtaining multiple measurements from the same individual within either a set period of time or a variety of conditions. They employ strategies such as repeated baseline measurements, varying reinforcement schedules, and/or counterbalancing different treatments. By collecting multiple data points from an individual in a controlled environment, N = 1 designs are able to identify unique patterns and changes in behavior that could be masked in other designs. They give researchers the ability to study individuals in a way that would be difficult to achieve in group designs, allowing for more precise examination of individual responses.

remove between subjects threats to validity baseline if stable indicates absence of extraneous factors