Control by stimulus features during fading.
Make the first discrimination obvious, then fade the prompt; otherwise learners stay glued to the prompt instead of the skill.
01Research in Context
What this study did
The team asked: can we teach preschoolers to pick the bigger circle by slowly dimming a bright light that first shows the answer?
They set up a two-choice game. One circle was always larger. A bright light covered the correct choice at first. The light grew dim across trials.
Kids got a candy for touching the bigger circle. The researchers watched if the children still chose correctly after the light was gone.
What they found
When the size difference was big, kids learned the rule even after the light vanished.
When the size difference was small, most kids just kept following the light. They never looked at the circles.
Starting with an easy size gap first, then moving to a harder one, fixed the problem.
How this fits with other research
Hawkes et al. (1974) used the same slow-fade idea to move autistic children from 1:1 teaching to a full classroom. Their success shows the lab trick works in real schools.
Whiting et al. (2015) later taught adults with severe ID to see tiny picture differences with prompts and fading. They proved the method works across ages and diagnoses.
Wichnick-Gillis et al. (2019) swapped the bright light for written scripts. Scripts faded out and kids with autism still talked to peers. The cue changed, the fading logic stayed the same.
Why it matters
Before you fade any prompt, check the skill is easy to see at the start. If the child keeps looking at the prompt instead of the task, make the target bigger, brighter, or louder first. Then fade. This saves you from prompt dependency and speeds up true learning.
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02At a glance
03Original abstract
Sixteen children were given four successive circle-size discrimination problems with luminance as the fading stimulus. Children who were first presented with a difficult size discrimination failed to acquire this discrimination. Those who first received an easy discrimination learned the difficult discrimination. At the end of each 10-trial block, two probe stimuli were presented to monitor any shift in control from luminance to size. One probe was the same size as the positive stimulus but of different luminance; the other was the same luminance but of different size. If, in the course of fading, size and luminance both controlled responding, fading was successful. If luminance alone controlled responding until the end of fading, the size discrimination was not established. Dual control, and thus successful fading, resulted when the target stimuli were very discriminable, or when the target stimuli were subtly different provided that previous fading series had first established less subtle discriminations.
Journal of the experimental analysis of behavior, 1979 · doi:10.1901/jeab.1979.31-177