Accuracy of performance on a matching-to-sample procedure under interval schedules.
Under fixed-interval schedules, matching accuracy dips mid-wait and fast responding keeps errors low.
01Research in Context
What this study did
Catania et al. (1972) ran a matching-to-sample task with pigeons.
Birds picked the comparison color that matched the sample.
Food arrived only after a fixed time passed.
The team watched how often the birds chose right at different points in the wait.
What they found
Accuracy dipped in the middle of the interval, then rose again near food.
When birds pecked fast, they made the fewest errors.
The pattern held across eight different wait times, from 30 seconds to 240 seconds.
How this fits with other research
Thomas (1968) first showed that response rate under fixed-interval schedules rises and falls in a smooth curve.
Catania et al. (1972) link that same curve to moment-by-moment accuracy, not just rate.
Rogers-Warren et al. (1976) later added a visible clock for people.
The clock let humans keep reinforcement while pecking less, the opposite of the high-rate rule seen in pigeons.
The studies do not clash: birds had no extra cues, so speed stayed their best guide.
LeBlanc et al. (2020) jump to today, showing that small layout changes on a data sheet can lift therapist accuracy during matching trials.
Together, the chain moves from basic pattern, to stimulus control, to real-world fidelity.
Why it matters
If you run fixed-interval programs, expect accuracy to sag mid-interval unless you add prompts or clocks.
Watch response speed: slow responding may flag an upcoming error burst.
For conditional-discrimination drills, consider inserting brief cues or faster trial pacing to keep accuracy high.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Add a brief visual prompt or timed trial cue halfway through your FI period to curb the mid-interval accuracy drop.
02At a glance
03Original abstract
Correct matches on a matching-to-sample procedure were reinforced under fixed-interval, chained fixed-interval, and fixed-interval schedules with exteroceptive stimulus changes correlated with time since the last reinforcer (an added clock). For all four pigeons, accuracy changed within the fixed-interval and fixed-interval schedules with added clock, decreasing from the beginning of the interval to some point in the middle. The performance then became increasingly more accurate until the end of the interval. Under the chained schedules, accuracy also changed within the components. During the initial component, accuracy decreased from the beginning of the fixed interval to some point in the middle or at the end. During the middle component, the performance usually remained at an intermediate level of accuracy. During the terminal component, the initially inaccurate performance became increasingly more accurate throughout the interval. Systematic relationships between response rate and per cent error showed that all four pigeons performed most accurately at high rates. The accuracy of the performance at low rates was also quite high. These relationships held for all three types of schedules through an eight-fold variation in scheduled interreinforcement time.
Journal of the experimental analysis of behavior, 1972 · doi:10.1901/jeab.1972.18-65