fixedratio

Fixed ratio is a term used in operant conditioning to describe a reinforcement schedule in which a reinforcer is delivered after a fixed number of correct responses. The schedule is denoted as FR n, where n is a positive integer. For example, FR-1 provides reinforcement after every response (continuous reinforcement), while FR-5 reinforces after every fifth response.

In terms of behavior, fixed-ratio schedules typically produce high and steady rates of responding, with a noticeable post-reinforcement pause after each reinforcement. As the required number of responses increases, the pause tends to lengthen and the overall response pattern can become a scalloped curve: short bursts of responding followed by brief pauses.

Applications of fixed-ratio schedules appear in both research and training contexts. In animal experiments, FR schedules help study motivation, learning, and the effects of effort on performance. In educational or workplace settings, fixed ratios can be used to shape consistent effort or productivity, such as requiring a set number of completed tasks before a reward is given.

Limitations and considerations include the potential for ratio strain, where very high ratios lead to a drop in responding or abrupt disengagement. Fixed ratios are also less flexible for maintaining behavior in changing conditions compared with variable schedules, which can sustain responding more resiliently under uncertainty. Researchers often compare fixed and variable ratio schedules to understand how predictability and work requirements influence motivation and effort.