<p>In behavior analysis, replication is one of the most fundamental strategies used to establish generality of results. However, replication is not restricted to just repeating an experiment, whether directly or systematically. Replication is also a defining component of many procedures used in individual experiments in behavior analysis. For example, some methods, such as single-stimulus discrimination procedures, exhibit direct control over behavior with a series of mini-AB designs (trial and intertrial periods) repeated multiple times within a single session. Once stimulus control is acquired, replication is demonstrated each time stimulus presentation is followed by the appropriate response. Conditional discrimination methods have the same structure with more trial types or stimuli that control response selections. So, replication is built in not only across experiments but also in within-session experimental designs. This will be illustrated by examples showing fine-grained data analysis. The illustrations will confirm Pennypacker’s emphasis that moment-to-moment analyses of behavior are essential to successful replication.</p>