In this Yale lecture from Everyday Parenting: The ABCs of Child Rearing, Dr. Alan Kazdin continues the course's troubleshooting discussion, addressing what happens when behavior change stalls even after a parent has followed the recommended techniques correctly. Kazdin offers deeper insight into why progress can slow or plateau, covering factors like changing circumstances, inconsistent follow-through across caregivers, and the need to periodically adjust reinforcement systems as a child grows. The lecture gives parents a set of practical next steps for diagnosing and resolving a stalled behavior plan rather than abandoning it. It builds directly on the first troubleshooting lecture, rounding out the course's guidance on sustaining behavior change over the long term.