Adjunctive Behavior

 Behavior that occurs as a collateral effect of a schedule of periodic reinforcement for other behavior; time-filling or interim activities (e.g., doodling, idle talking, smoking, drinking) that are induced by schedules of reinforcement during times when reinforcement is unlikely to be delivered. Also called schedule-induced behavior.

Alternative Schedule (alt)

Provides reinforcement whenever the requirement of either a ratio schedule or an interval schedule--the basic schedules that makeup the alternative schedule--is met, regardless of which of the component schedule's requirements is met first.

Behavioral Contrast

The phenomenon in which a change in one component of a multiple schedule that increases or decreases the rate of responding on that component is accompanied by a change in the response rate in the opposite direction on the other, unaltered component of the schedule.

Chained Schedule (chain)

A schedule of reinforcement in which the response requirements of two or more basic schedules must be met in a specific sequence before reinforcement is delivered; a discriminative stimulus is correlated with each component of the schedule.

Compound Schedule of Reinforcement

A schedule of reinforcement consisting of two or more elements of continuous reinforcement (CRF), the four intermittent schedules of reinforcement (FR, VR, FI, VI), differential reinforcement of various rates of responding (DRH, DRL), and extinction. The elements from these basic schedules can occur successively or simultaneously and with or without discriminative stimuli; reinforcement may be contingent on meeting the requirements of each element of the schedule independently or in combination with all elements.

Concurrent Schedule (conc)

A schedule of reinforcement in which two or more contingencies of reinforcement (elements) operate independently and simultaneously for two or more behaviors.

 Is in effect whenever reinforcement follows the completion of response requirements for both a ratio schedule and an interval schedule of reinforcement.

Continuous Reinforcement (CRF)

 A schedule of reinforcement that provides reinforcement for each occurrence of the target behavior.

Differential Reinforcement of Diminishing Rates (DRD)

A schedule of reinforcement in which reinforcement is provided at the end of a predetermined interval contingent on the number of responses emitted during the interval being fewer than a gradually decreasing criterion based on the individual's performance in previous intervals (e.g., fewer than five responses per 5 minutes, fewer than four responses per 5 minutes, fewer than three responses per 5 minutes).

Differential Reinforcement of High Rates (DRH)

A schedule of reinforcement in which reinforcement is provided at the end of a predetermined interval contingent on the number of responses emitted during the interval being greater than a gradually increasing criterion based on the individual's performance in previous intervals (e.g., more than three responses per 5 minutes, more than five responses per 5 minutes, more than eight responses per 5 minutes).

Differential Reinforcement of Low Rates (DRL)

 A schedule of reinforcement in which reinforcement (A) follows each occurrence of the target behavior that is separated from the previous response by a minimum interresponse time (IRT) or (B) is contingent on the number of responses within a period of time not exceeding a predetermined criterion. Practitioners use DRL schedules to decrease the rate of behaviors that occur too frequently but should be maintained in the learner's repertoire.

Fixed Interval (FI)

A schedule of reinforcement in which reinforcement is delivered for the first response emitted following the passage of a fixed duration of time since the last response was reinforced (e.g., on an FI 3-minute schedule, the first response following the passage of 3-minutes is reinforced).

Fixed Ratio (FR)

A schedule of reinforcement requiring a fixed number of responses for reinforcement (e.g., an FR 4 schedule reinforcement follows every fourth response).

Intermittent Schedule of Reinforcement (INT)

A contingency of reinforcement in which some, but not all, occurrences of the behavior produce reinforcement.

Lag Reinforcement Schedule

A schedule of reinforcement in which reinforcement is contingent on a response being different in some specified way (e.g., different topography) from the previous response (e.g., Lag 1) or a specified number of previous responses (e.g., Lag 2 or more)

Limited Hold

 A situation in which reinforcement is available only during a finite time following the elapse of an FI or VI interval; if the target response does not occur within the time limit, reinforcement is withheld and a new interval begins (e.g., on an FI 5-minute schedule with a limited hold of 30 seconds, the first correct response following the elapse of 5 minutes is reinforced only if that response occurs within 30 seconds after the end of the 5-minute interval).

Matching Law

The allocation of responses to choices available on concurrent schedules of reinforcement; rates of responding across choices are distributed in proportions that match the rates of reinforcement received from each choice alternative.

Mixed Schedule of Reinforcement (mix)

A compound schedule of reinforcement consisting of two or more basic schedules of reinforcement (elements) that occur in an alternating, usually random, sequence; no discriminative stimuli are correlated with the presence or absence of each element of the schedule, and reinforcement is delivered for meeting the response requirements of the element in effect at any time

Multiple Schedule (mult)

A compound schedule of reinforcement consisting of two or more basic schedules of reinforcement (elements) that occur in an alternating, usually random, sequence; a discriminative stimulus is correlated with the presence or absence of each element of the schedule, and reinforcement is delivered for meeting the response requirements of the element in effect at any time.

Postreinforcement Pause

 The absence of responding for a period of time following reinforcement; an effect commonly produced by fixed interval (FI) and fixed ratio (FR) schedules of reinforcement

Progressive Schedule of Reinforcement

A schedule that systematically thins each successive reinforcement opportunity independent of the individual's behavior; progressive ratio (PR) and progressive interval (PI) schedules are thinned using arithmetic or geometric progressions.

Progressive-Ratio (PR) Schedule of Reinforcement

 A variation of the fixed ratio (FR) schedule of reinforcement that increases the ratio requirements incrementally within the session; PR schedule requirements are changed using (a) arithmetic progressions to add a constant number to each successive ratio, or (b) geometric progressions to add successively a constant proportion of the preceding ratio.

Ratio Strain

A behavioral effect associated with abrupt increases in ratio requirements when moving from denser to thinner reinforcement schedules; common effects include avoidance, aggression, and unpredictable pauses or cessation in responding.

Schedule of Reinforcement

A rule specifying the environmental arrangements and response requirements for reinforcement; a description of a contingency of reinforcement.

Schedule Thinning

Changing a contingency of reinforcement by gradually increasing the response ratio or the extent of the time interval; it results in a lower rate of reinforcement per responses, time, or both.

Tandem Schedule (tand)

A schedule of reinforcement identical to the chained schedule except, like the mix schedule, the tandem schedule does not use discriminative stimuli with the elements in the chain.

Variable Interval (VI)

 A schedule of reinforcement that provides reinforcement for the first correct response following the elapse of variable durations of time occurring in a random or unpredictable order. The mean duration of the intervals is used to describe the schedule (e.g., on a VI 10-minute schedule, reinforcement is delivered for the first response following an average of 10 minutes since the last reinforced response, but the time the elapses following the last reinforced response might range from 30 seconds or less to 25 minutes or more).

Variable Ratio (VR)

A schedule of reinforcement requiring a varying number of responses for reinforcement. The number of responses required varies around a random number; the mean number of responses required for reinforcement is used to describe the schedule (e.g., on a VR 10 schedule an average of 10 responses must be emitted for reinforcement, but the number of responses required following the last reinforced response might range from 1 to 30 or more).