Concurrent schedule

Concurrent means options are available together

In a classic laboratory arrangement, two keys are present and each operates on its own variable-interval schedule. Responding can move between them. At home, a person might choose between conversation, a game, and independent reading, each with different histories and current consequences.

The alternatives need operational definitions. An apparent choice between two buttons may also include looking away, asking for help, leaving, or another option. Excluding those responses can distort the analysis.

Choice appears as response allocation

Analysts may measure responses, time, selections, or another unit allocated to each option. The denominator includes the complete eligible set during the defined observation period.

For 30 minutes of free choice, time on drawing divided by total time allocated across defined options answers a different question from the count of switches or first selections. State the unit before interpreting preference.

The matching law describes a relation

The matching-law tutorial explains the common finding that relative responding often tracks relative obtained reinforcement under concurrent schedules. If one alternative produces 60% of obtained reinforcement, behavior may approach a comparable allocation.

Matching is a quantitative relation across observations, not a rule that every choice must obey. Bias and sensitivity can reflect quality, effort, delay, instructions, discriminability, history, or measurement. One equal ratio does not demonstrate the law.

Several consequence dimensions matter

Reinforcement rate receives much attention, but quality, magnitude, immediacy, and response effort also influence choice. A lower-rate option with a highly valued, immediate outcome may draw more behavior than a higher-rate alternative.

Staddon and Cerutti’s review surveys operant choice, concurrent schedules, matching, timing, and theoretical limits. It shows why response allocation reflects a dynamic system rather than a simple reward count.

Concurrent, multiple, and concurrent-chain schedules differ

In a concurrent schedule, alternatives operate together. In a multiple schedule, components alternate and each is correlated with a distinct stimulus. In concurrent chains, an initial choice leads to different terminal schedule components.

These arrangements answer different questions. A clinic plan should name which options are simultaneously available and which consequences follow each response.

Applied use requires complete options

Concurrent schedules can help analyze communication choices, work options, leisure allocation, or appropriate and unsafe response classes. A review of concurrent reinforcement for problem and appropriate behavior highlights how rate, quality, delay, and bias can influence allocation.

Clinical use should avoid treating access to communication, food, water, bathroom use, mobility, prescribed care, relationships, or emergency help as bargaining options. Dissent, health, and safety retain their own authority.

A fictional allocation record

During 20 defined choice opportunities, Kai selects the quiet reading area 12 times and the collaborative puzzle table 8 times. The reading choice produces the planned outcome in 9 opportunities; the puzzle choice does so in 6.

Response allocation is 12/20, or 60%, to reading and 8/20, or 40%, to puzzles. Obtained outcomes are 9/15, or 60%, from reading and 6/15, or 40%, from puzzles. Equal proportions in one short record do not establish matching or causation. Effort, social context, quality, and position also differ.

Measurement needs a locked cohort

Define each response option, the observation window, opportunity or time denominator, obtained reinforcer, schedule, changeover, exclusions, and other available behavior. Report absolute counts alongside relative measures.

When outcomes depend on behavior, obtained reinforcement and response allocation influence each other. Descriptive data can support hypotheses and need stronger comparison for causal conclusions.

The BACB outline supplies broad scope

The BACB BCBA Test Content Outline, 6th edition covers reinforcement schedules, motivating operations, stimulus control, measurement, experimental design, and interpretation. It is examination content, not a person-specific schedule prescription.

A qualified clinician should select applied contingencies through assessment, collaboration, direct evidence, and applicable ethical safeguards.

Questions clinicians can ask

Ask which alternatives are truly available at the same time, which response unit is measured, and what outcome each option produces. Clarify quality, amount, delay, effort, changeover, instructions, setting, and history.

Ask whether the analysis includes refusal, help-seeking, and inactivity. Then separate descriptive allocation from an experimentally supported relation.

Meaningful choice requires more than two visible buttons. Both alternatives must be accessible, understandable, and realistically obtainable under the described schedule. Switching costs, staff approval, mobility, communication effort, and delayed availability can make an option nominal rather than functional. Record when an alternative was unavailable or when the person attempted a response that the system failed to recognize. Those events belong in the denominator review instead of being recoded as preference for the other option.