A hospital patient may press a button for pain medication, but the pump delivers at most one dose per hour. This is which schedule?

1. The reward depends on how much time has passed rather than on how many times the button is pressed, so this is an interval schedule. 2. The waiting time is set and predictable at one hour, so it is fixed rather than variable. 3. It is therefore a fixed-interval schedule, the chapter's worked example of patient-controlled pain relief. 4. Fixed-interval schedules produce a scallop-shaped pattern with a significant pause after each reinforcement, since responding before the hour is up is never rewarded. _Source: OpenStax Psychology (1st ed., CC BY 4.0), Ch 6 "Learning", §6.3 Operant Conditioning_