An analysis of procedures that affect response variability
Use fixed or variable lag 4 plus a simple visual cue to spark new responses and turn repetition on or off like a switch.
01Research in Context
What this study did
Dracobly et al. (2017) asked children to press colored keys in any order they wanted.
The team compared two rules: fixed lag 4 and variable lag 4.
Kids earned a prize only if their last four presses differed from the four before.
Colorful lights told them when the game wanted new patterns or allowed repeats.
What they found
Both lag rules quickly boosted novel key orders for most children.
The lights let kids flip between repeating and varying in seconds.
Variable lag 4 gave slightly more creative patterns than fixed lag 4.
How this fits with other research
Olin et al. (2020) later used the same logic with autistic children.
They added echoic prompts and got flexible answers to social questions.
Allen et al. (2016) used colored placemats the same way Dracobly used lights.
Green mat meant vary your mands; red mat meant stay the same.
Together these studies show one clear rule: pair a signal with the lag rule and kids switch gears fast.
Why it matters
You can copy the light trick in your session today.
Pick one task—stacking blocks, naming animals, or typing codes.
Set a lag 4 rule and hold up a green card when you want variety.
Drop the card when repetition is okay.
No extra tokens, no long lecture—just the card cues the shift.
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02At a glance
03Original abstract
Response variability is sensitive to antecedent and consequent manipulations. Researchers have investigated inducement, direct production through reinforcement, and stimulus control of response variability. Recently, researchers have shown that lag reinforcement schedules reliably increase variability but may also produce higher-order stereotypy. There has been limited investigation of appropriate variability levels and alternation between repetition and variation. In a three-part study, we evaluated levels of variability across a group of children, the effects of various procedures on producing response variability and novelty, and the use of schedule-correlated stimuli for producing rapid alternation between repetition and variation. In Study 1, there was a nearly bimodal distribution of children emitting either low or high variability. In Study 2, for most children, fixed lag 4 and variable lag 4 schedules produced the highest levels of variability and novelty. In Study 3, responding was brought under control of schedule-correlated stimuli, allowing for rapid alternation between repetition and variation.
Journal of Applied Behavior Analysis, 2017 · doi:10.1002/jaba.392