Preference and resistance to change with constant-duration schedule components.
Fixed-time work periods make both preference and resistance to disruption stronger than variable periods.
01Research in Context
What this study did
The team worked with pigeons on two-key concurrent-chain schedules.
Each key led to a terminal link that stayed open for the same short time every trial.
They compared this steady setup to links that ended at random times.
Birds chose first, then produced responses for food in the chosen link.
What they found
When the terminal link lasted a fixed amount of time, the birds’ choice almost perfectly tracked the real payoff ratio.
The same steady timing also made responding in that link harder to disrupt with free food elsewhere.
In plain words, fixed-duration components made both preference and staying power stronger.
How this fits with other research
Pilgrim et al. (2000) ran the same comparison the same year and saw the same boost in preference and resistance.
The two papers are direct replications, giving double evidence that timing regularity sharpens choice.
Cicerone (1976) earlier showed that fixed-interval schedules create the clearest temporal control; the new study extends that idea to choice and resistance.
Fantino (1969) found choice follows expected wait time, not just rate. Fixed-duration links give a clearer wait signal, so the tighter matching seen here fits that older rule.
Why it matters
You can tighten up a client’s preference for a task by keeping the work period the same each time.
Predictable timing gives the learner a clearer picture of when reinforcement will arrive.
Try setting a fixed 30-second work interval before each break and watch choice and persistence rise.
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02At a glance
03Original abstract
Previous research on preference between variable-interval terminal links in concurrent chains has most often used variable-duration terminal links ending with a single reinforcer. By contrast, most research on resistance to change in multiple schedules has used constant-duration components that include variable numbers of reinforcers in each presentation. Grace and Nevin (1997) examined both preference and resistance in variable-duration components; here, preference and resistance were examined in constant-duration components. Reinforcer rates were varied across eight conditions, and a generalized-matching-law analysis showed that initial-link preference strongly over-matched terminal-link reinforcer ratios. In multiple schedules, baseline response rates were unaffected by reinforcer rates, but resistance to intercomponent food, to extinction, and to intercomponent food plus extinction was greater in the richer component. The between-component difference in resistance to change exhibited additive effects for the three resistance tests, and was systematically related to reinforcer ratios. However, resistance was less sensitive to reinforcer ratios than was preference. Resistance to intercomponent food and to intercomponent food plus extinction was more sensitive to reinforcer ratios in the present study than in Grace and Nevin (1997). Thus, relative to variable-duration components, constant-duration components increased the sensitivity of both preference and relative resistance, supporting the proposition that these are independent and convergent measures of the effects of a history of reinforcement.
Journal of the experimental analysis of behavior, 2000 · doi:10.1901/jeab.2000.74-79