What is the characteristic feature of a Fixed Ratio schedule?

The characteristic feature of a Fixed Ratio schedule is that reinforcement is provided after a set number of responses. This means that a specific number of behaviors or actions must occur before the reinforcement is delivered. For example, in a Fixed Ratio 5 schedule, a subject would need to perform the target behavior five times before receiving a reward.

This schedule creates a predictable pattern that can motivate individuals to engage in the behavior more frequently, as they are aware of the exact amount of effort required to earn a reward. The timing of reinforcement is consistent and directly linked to the number of responses, which is a distinguishing aspect of Fixed Ratio schedules compared to other reinforcement types.

The other options describe different types of reinforcement schedules. For instance, schedules based on time intervals pertain to interval schedules rather than ratio schedules. Also, reinforcing every instance of the behavior refers to continuous reinforcement, not Fixed Ratio. Lastly, reinforcement given at unpredictable times points to a Variable Interval or Variable Ratio schedule, which contrasts with the predictability found in Fixed Ratio schedules.