Figure 2.

Correct academic responses per minute (top row) during contingent reinforcement (open circles), noncontingent reinforcement (filled triangles), and no reinforcement (filled circles) schedules. Cumulative initial-link selections (second row) during the continuous reinforcement (CRF) and intermittent reinforcement (INT) preference assessments. Reinforcers delivered per minute (third row) and contingency strength values for contingent (fourth row) and noncontingent (bottom row) reinforcement sessions for Tim.