There are 2 different interval schedules and 2 different ratio schedules.
1. Fixed-ratio schedules: where a response is reinforced but only after a specified number of responses. It produces a high, steady rate of responding with a brief pause after the delivery of the reinforcer.
2. Variable-ratio schedules: happens when a response is reinforced after an unknown amount of responses. These type of schedules create a high steady rate of responding.
3. Fixed-interval schedules: schedules where the first response is rewarded but only after the time given has passed. It causes high amounts of responding near the end, but a lot slower responding right after the delivery of the reinforcer.
4. Variable-interval schedules: happens when a response is rewarded after an unknown amount of time has gone by. In this type of schedule the responses are produced at a slow, steady rate.