What is a key characteristic of a variable ratio schedule?

A key characteristic of a variable ratio schedule is that reinforcement is delivered based on an unpredictable number of responses. This means that the subject does not know when the next reinforcement will occur, which creates a high and steady rate of responding. Individuals tend to keep trying to receive more rewards because the successful response could happen at any time, leading to a high degree of persistence. This schedule is commonly associated with behaviors such as gambling, where the outcome is uncertain.

In contrast, a fixed ratio schedule involves reinforcement given after a set number of responses, which leads to pauses after reinforcement. A variable interval schedule involves reinforcement after varying amounts of time, and continuous reinforcement provides a reward after every response, which can lead to rapid extinction when reinforcement stops. These variations highlight the unique nature of the variable ratio schedule, where unpredictability encourages ongoing engagement.