A comparison of synchronous and noncontingent stimulus delivery on task engagement
Delivering reinforcement right as the behavior happens beats giving the same items on a timer, even when kids say they like the timer method.
01Research in Context
What this study did
Hardesty et al. (2023) compared two ways to give reinforcement. One group got it right when they were on task. The other group got the same items on a fixed timer, no matter what they did.
They used an alternating-treatments design. Kids saw both setups in mixed order. The team tracked on-task behavior and asked which way the kids liked best.
What they found
Synchronous reinforcement won. Kids stayed on task more when the reward came right with the behavior.
Surprise twist: the children liked the noncontingent schedule just as much. Task liking did not change in either condition.
How this fits with other research
Diaz de Villegas et al. (2024) ran a near copy with preschoolers and saw the same win for synchronous plus a clear kid preference for it. The 2023 study shows the effect holds even when kids do not prefer the better schedule.
Gomes et al. (2025) moved the idea to a whole-class game. A quick group contingency still beat noncontingent goodies for rule-following and cut disruption.
Chou et al. (2010) showed most kids like earning their treats until the schedule gets very lean, then they switch to free stuff. Hardesty’s data fit this pattern: kids picked the easier, noncontingent option even though it worked less well.
Why it matters
You can boost attention without needing extra rewards—just time them right. Keep the delivery synced to the behavior you want, even if the learner says they like the free-goodie version. Preference and performance can split; follow the data, not the smile. Try a quick 30-second check: if the child is on task, hand over the token or praise right then. If not, skip and wait for the next chance.
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02At a glance
03Original abstract
Synchronous schedules of reinforcement are those in which the onset and offset of a reinforcer are synchronized with the onset and offset of a target behavior. The current study replicated and extended Diaz de Villegas et al. (2020) by comparing synchronous reinforcement to noncontingent stimulus delivery while evaluating on-task behavior of school-age children. A concurrent-chains preference assessment was then used to determine the preferred schedule. Results indicated that the synchronous schedule was more effective than the continuous, noncontingent delivery of the stimulus at increasing on-task behavior but that the children preferred noncontingent delivery. Additionally, the use of synchronous and noncontingent delivery did not alter the children's preference for the task.
Journal of Applied Behavior Analysis, 2023 · doi:10.1002/jaba.986