FR, VR, FI and VI: schedules of reinforcement
A schedule of reinforcement says when a behavior earns the reinforcer. Two questions sort the four basic intermittent schedules: is it counted in responses (ratio) or in time (interval), and is the requirement the same every time (fixed) or does it change around an average (variable)?
| Schedule | Reinforcer is delivered | Example |
|---|---|---|
| FR 5 (fixed ratio) | After every 5th response | A token after every 5 correctly sorted cards. |
| VR 5 (variable ratio) | After a changing number of responses that averages 5 | A token after the 3rd, then the 7th, then the 5th correct card. |
| FI 2 min (fixed interval) | For the first response after 2 minutes have passed | Praise for the first hand raise once 2 minutes are up; earlier hand raises earn nothing. |
| VI 2 min (variable interval) | For the first response after a changing time that averages 2 minutes | Praise for the first hand raise after 1 minute, then after 3, then after 2. |
Points that come up in practice questions
- Continuous reinforcement (CRF, the same as FR 1) reinforces every response. It is the usual choice while a skill is new.
- Once a skill is learned, thinning to an intermittent schedule helps it hold up when reinforcement is not always there.
- Variable schedules tend to give steadier responding than fixed ones, and variable ratio tends to give the highest rates.
- Fixed interval often shows a pause after each reinforcer and faster responding as the interval ends (a "scallop").
- In an interval schedule time alone earns nothing: the response must still happen after the interval ends.
- Your supervisor sets the schedule in the plan; a technician follows it and records the data.
Try the free 20-question practice test, or read about DRA, DRI, DRO and DRL and prompting hierarchies.
Want three full-length practice exams? The Behavior Technician Exam Prep Pack costs $32 on Gumroad: a PDF study guide, three 85-question practice exams with answer keys and rationales, and 96 flashcards. It is our own paid product, so this link is a commercial link and not a neutral recommendation.