Chained schedule

Components occur in a fixed sequence

Imagine two schedule components. A blue card signals the first requirement. Completing it produces a green card that signals the second requirement. Completing the second produces the terminal reinforcer.

The order and distinct component signals are defining features. Presenting several requirements at once or allowing free choice among them describes a different arrangement.

Each transition can have two functions

The stimulus produced after one component can reinforce completion of that component because it leads closer to the terminal outcome. The same stimulus signals which response and schedule operate next.

Those functions should be evaluated from behavior and arrangement. Simply labeling a visual card a “reinforcer” does not demonstrate that it strengthened the preceding response.

A chained schedule differs from a behavior chain

A behavior chain is a sequence of responses in which each step changes the environment and sets the occasion for the next step. This schedule-of-reinforcement arrangement instead uses successive signaled components.

The two can overlap in practice. Preparing a snack may contain a response chain, while access to a chosen activity follows completion of two signaled work components. Name the unit under analysis so procedures and measures stay clear.

Compare related compound schedules

In a multiple schedule, signaled components alternate, and each component has its own schedule. They need not occur in one fixed sequence before a single terminal reinforcer.

In a tandem schedule, components occur in sequence without distinct component stimuli. In a concurrent schedule, two or more schedules are available at the same time. The BACB BCBA Test Content Outline asks entry-level certificants to distinguish concurrent, multiple, mixed, and chained schedules.

A fictional practice example

Jordan chooses a two-part routine before music time. A picture of a backpack signals putting away three materials. Completion produces a headphones card, which signals a fixed-ratio two communication routine: choose a playlist and confirm volume. Completion produces ten minutes of the selected music.

Across eight opportunities, Jordan completes the first component in 7 of 8, transitions within 20 seconds in 5 of 7 completed first components, and completes the second component in 4 of 5 entered components. Terminal reinforcement follows 4 of 4 completed sequences.

These denominators answer different questions. Pooling them into one accuracy percentage would hide the transition gap.

Define every component before use

For each component, record its signal, response, schedule requirement, completion rule, duration, prompt options, error response, and produced event. Define the terminal reinforcer and how preference will be checked.

Specify what happens after interruption, equipment failure, withdrawal, illness, a missed transition, or an unavailable outcome. Avoid improvising extra requirements after the sequence begins.

Watch for long pauses and weak links

Early components can show long initial pauses when the terminal reinforcer is distant or the overall requirement is too effortful. One transition can become a weak link because the signal is unclear, the response is difficult, or the produced event has little reinforcing value.

Graph latency, duration, response rate, accuracy, transition time, prompts, and completion by component. A single total-duration measure can conceal where the sequence breaks down.

Protect choice and basic access

A chain should serve a meaningful goal selected by or agreed to with the person. Keep communication, food, water, bathroom access, mobility, prescribed care, and emergency help available regardless of performance.

Do not turn every preferred activity or relationship into a terminal payment. Offer authentic choices, honor accessible pause and withdrawal signals, and monitor distress, avoidance, and opportunity cost.

A planning checklist

• What makes the full sequence useful to the person?
• Which distinct stimulus signals each component?
• What schedule operates in each component?
• What event links one component to the next?
• What terminal outcome was selected and recently preferred?
• How are prompts, errors, pauses, and interruptions handled?
• Which measure identifies the weak component or transition?
• When will the sequence be shortened, faded, revised, or stopped?

Report both successful sequences and incomplete opportunities. Preserve the reason for each exclusion.

Change one schedule feature at a time

When the full sequence is too effortful, revise the component supported by data. Options can include reducing one ratio, improving its signal, inserting practice, increasing the value or immediacy of the terminal outcome, or teaching an accessible transition response. Document the change date and keep prechange data separate. Simultaneous changes may help the person, though they limit conclusions about which feature mattered.