This study evaluated the effects of four instructional variants on instruction following under changing reinforcement schedules using an operant task based on Hackenberg and Joker's "Journal of the Experimental Analysis of Behavior," 62, 367-383 (1994) experimental preparation. Sixteen college-aged adults served as participants and were randomly assigned to one of four instruction conditions (directive, generic, non-directive, and control). Results suggest textual verbal behavior modulated instruction following. Specifically, directive and generic instructions produced greater levels of instructional control and relatively lower levels of schedule control compared to non-directive instructions. Thus, participants in the directive and generic groups responded in accordance with the instructions even when schedules of reinforcement favored deviation from the instructed pattern. In contrast, participants in the non-directive group responded toward the optimal pattern. In the control condition, participant responding was variable but toward the optimal pattern. Findings are interpreted within the framework of Skinner's analysis of verbal behavior and formulation of rule governance.