Preference for simple interval schedules of reinforcement in concurrent chains: Effects of segmentation ratio.
Adding segments to a schedule hurts preference, but placing the first payoff early softens the blow.
01Research in Context
What this study did
The team worked with pigeons in a two-key cage.
Each key led to a different food schedule.
One schedule was a plain fixed-interval.
The other was the same interval split into a chain with extra signals.
They varied how early in the chain the first food appeared.
Birds could hop keys any time, showing which schedule they liked.
What they found
Birds almost always pecked the plain-interval key more.
The sooner the chained schedule paid off, the less the birds hated it.
Still, even a small split made the simple schedule win.
Longer waits at the end of the chain made the dislike stronger.
How this fits with other research
Wacker et al. (1985) and Warren et al. (1986) saw the same bird choice pattern: simple beats chained.
The 1988 study adds the new twist that the timing of the first reinforcer inside the chain matters.
Henton (1972) looks like a contradiction: his pigeons did not care between chained and tandem.
The gap is size: W used only two short links, so the delay cost was too small to see.
When segmentation grows, the simple schedule pulls ahead.
Why it matters
For humans, extra rules or token steps can feel like added delay.
Keep reinforcement lean and direct when you want quick engagement.
If you must use chains, put the first reinforcer early and keep terminal waits short.
Check client preference data; simpler is usually better.
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02At a glance
03Original abstract
A concurrent-chains procedure was used to examine pigeons' preferences between segmented and unsegmented terminal-link schedules of reinforcement. During the initial link, a pair of independent, concurrent variable-interval 60-s schedules was in effect. In the terminal link, reinforcement was provided by a chain fixed-interval fixed-interval schedule on one key and by a simple fixed-interval schedule with an equal interreinforcement interval in the other. The relative duration between the first and second components (segmentation ratio) in the terminal-link chained schedule was systematically varied while the terminal-link duration was kept constant at either 15 s or 30 s in two sets of conditions. With few exceptions, the simple schedule was preferred to the chained schedule. Furthermore, this preference was inversely related to the size of the segmentation ratio in the segmented schedule. When the segmentation ratio was smaller than 1:1, preference was more extreme for a 30-s condition than for a 15-s condition. However, preference decreased more rapidly in conditions with the longer terminal-link duration when the ratio increased. Taken together, these results were consistent with previous findings concerning the effect of the terminal-link duration on choice between segmented and unsegmented schedules. In addition, the data suggested that segmentation ratio in a segmented schedule constitutes another potent factor influencing preference for the unsegmented schedule.
Journal of the experimental analysis of behavior, 1988 · doi:10.1901/jeab.1988.49-9