A schedule of reinforcement is the rule that says which responses get reinforced. Change the rule and you change the pattern of behavior.
Why it matters
Every program includes a schedule, even when nobody names it. Teaching a new skill usually starts with reinforcement for every correct response. Keeping that skill going at home, at school, or on the job means moving to intermittent reinforcement that caregivers and teachers can actually sustain. If you thin too fast, responding falls apart. If you pick the wrong kind of schedule, you can get long pauses or slow, sluggish work.
Key ideas
- Continuous vs. intermittent. Continuous reinforcement (CRF) reinforces every occurrence of the response. It is ideal for acquisition. Any schedule that reinforces only some responses is intermittent, and intermittent schedules are better for maintenance.
- Two questions name any simple schedule.
- Ratio or interval? Ratio schedules depend on the number of responses. Interval schedules depend on the passage of time, and then a response.
- Fixed or variable? Fixed means the requirement is the same every time. Variable means it changes around an average.
- Interval schedules still require a response. On FI and VI, reinforcement goes to the first response after the interval has elapsed. Responses made earlier in the interval have no effect. If the reinforcer arrives when time runs out regardless of behavior, that is a time-based (fixed-time or variable-time) schedule, not an interval schedule.
- Each schedule has a typical pattern.
- FR: high rate, with a pause after each reinforcer, then a quick return to steady responding ("break and run"). Larger ratios produce longer pauses.
- VR: high, steady rate with little or no post-reinforcement pause, because the next reinforcer could come after any response.
- FI: a pause after reinforcement, then responding that speeds up as the end of the interval nears. On a cumulative record this looks like a scallop.
- VI: a steady, low-to-moderate rate with few pauses. Responding more quickly does not make reinforcement come any sooner.
- Ratio schedules usually produce higher rates than interval schedules, because on a ratio schedule a faster response rate earns reinforcement sooner.
- Variable schedules tend to produce more consistent responding than their fixed counterparts, and intermittent schedules in general produce behavior that is more persistent in extinction than CRF.
Definitions
- Fixed ratio (FR): reinforcement follows a set number of responses. FR 5 means every fifth response. FR 1 is the same as CRF.
- Variable ratio (VR): reinforcement follows a number of responses that varies around an average. On VR 5, the requirement might be 2, then 8, then 5.
- Fixed interval (FI): the first response after a set amount of time has passed is reinforced. FI 3 min means the first response once 3 minutes have elapsed.
- Variable interval (VI): the first response after an amount of time that varies around an average is reinforced.
- Post-reinforcement pause: a period without responding right after a reinforcer, typical of fixed schedules.
- Ratio strain: a breakdown in responding (long pauses, avoidance, quitting, sometimes problem behavior) when a ratio requirement is raised too quickly or set too high.
- Limited hold: a rule added to an interval schedule that keeps reinforcement available for only a short window once the interval ends.
Examples from a session
Four schedules in practice
- FR: In a vocational program, Darnell, an adult client, earns a break after every 10 assembled kits (FR 10). His data show a short pause after each break, then fast, steady assembly.
- VR: During reading practice at school, Mei gets a token after an average of 4 correctly read words, sometimes after 2 and sometimes after 6. She reads steadily without stopping after each token.
- FI: At home, a parent checks a timer every 15 minutes and praises the first instance of Ezra, age 7, playing quietly with his sister after the timer has gone off. Over several days, Ezra's quiet play tends to drop off right after praise and pick up as the 15 minutes run out.
- VI: In a clinic, an RBT delivers attention for the first on-task response after unpredictable intervals averaging 2 minutes. On-task behavior stays fairly even across the session.
Schedule thinning is usually done in small steps (for example FR 2 to FR 3 to FR 5) while the data are monitored. Longer pauses or new escape behavior after a step up signal ratio strain; the usual fix is to return to the last requirement that worked and thin more gradually.
Tip
These classic patterns come mostly from laboratory research. In people, instructions and rules can change them, so expect real data to be messier.
Common mistakes / exam traps
- Calling a time-based delivery an interval schedule. If no response is required, it is fixed-time or variable-time, not FI or VI.
- Thinking interval schedules reinforce every response during the interval. Only the first response after the interval ends counts.
- Assuming "variable" means random with no average. Variable schedules are described by their mean value (VR 10, VI 30 s).
- Confusing ratio strain with extinction. In ratio strain, reinforcement is still available, but the requirement is too large for the current behavior.
Exam trap
Ask "Is it counting responses or timing?" first, then "Is the requirement the same every time?" The answer to those two questions names the schedule. A reinforcer that arrives on the clock no matter what the learner does is a time-based schedule.
Exam trap
FR vs. FI from a cumulative record. Both fixed schedules show a pause after each reinforcer, so a pause alone does not decide it. Look at how responding resumes. An abrupt switch to a steep, straight, high rate (break and run) points to FR. A gradual speed-up that curves into a scallop points to FI.
Quick check
During a clinic session, Nora's RBT reinforces the first request for help that occurs after a varying period has passed, sometimes 1 minute, sometimes 5, averaging about 3 minutes. Which schedule is this?
Related topics
- Positive vs. negative reinforcement (B.4)
- Compound schedules: concurrent, multiple, mixed, and chained (B.10)
- Operant vs. respondent extinction, as procedure and as process (B.11)
- The matching law and how responding is allocated (B.23)
- Time-based reinforcement schedules, such as fixed-time (G.3)
- Maintaining change after intervention: schedule thinning and natural reinforcers (G.16)