Luana is learning to stay in her seat and work on her language arts tasks without talking to friends around her. She has been working on this new behavior for a week. During the first week, Ms. Kalani reinforces Luana every time Luana completes one of the tasks without talking. Now Ms. Kalani wants to use the reinforcement schedule that is most likely to result in the greatest persistence from Luana. What reinforcement schedule will be most effective in meeting her goal?