ABA Fundamentals

The effects of errors on children's performance on a circle-ellipse discrimination.

Stoddard et al. (1967) · Journal of the experimental analysis of behavior 1967
★ The Verdict

Start hard, allow an error, then back up—kids finish with keener visual skills than if you creep forward error-free.

✓ Read this if BCBAs teaching visual discriminations to early-elementary or braille learners.
✗ Skip if Practitioners who only run errorless programs and never fade difficulty.

01Research in Context

01

What this study did

The team asked kids to tell circles from ellipses.

Some kids started with easy pairs. Others began with shapes that looked almost the same.

If a child picked wrong, the program backed up to an easier pair. The control group only moved forward after each correct pick.

02

What they found

Kids who were allowed to fail at the hard pairs first ended up spotting tinier differences later.

The error-first group beat the error-free group on the final, hardest tests.

03

How this fits with other research

Toussaint et al. (2017) later used the same back-up-after-error plan to teach braille letters to blind children. Their results extend this 1967 study to a new sense and new population.

Sanders et al. (1989) also worked with child matching tasks, but they taught identity and oddity instead of shape size. Both labs show kids can learn fine visual rules without first drilling every tiny step.

Zeiler (1968) ran a similar idea on pigeons the next year. The bird data act as an animal model that supports the basic rule: error plus backup sharpens later control.

04

Why it matters

You can speed up fine discrimination teaching by letting the learner fail once or twice at the hardest level, then quickly dropping back. The brief failure seems to highlight the key difference. Try starting your next visual program one step above the child’s known pass level; if they miss, slide back one notch and climb again.

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Begin your next shape or letter set at the hardest pair, let one error occur, then drop to an easier pair before inching back up.

02At a glance

Intervention
prompting and fading
Design
quasi experimental
Population
neurotypical
Finding
positive
Magnitude
large

03Original abstract

Children first learned by means of a teaching program to discriminate a circle from relatively flat ellipses. Children in the control group then proceeded into a program which gradually reduced the difference between the circle and the ellipses. They advanced to a finer discrimination when they made a correct choice, and reversed to an easier discrimination after making errors ("backup" procedure). The children made relatively few errors until they approached the region of their difference threshold (empirically determined under the conditions described). When they could no longer discriminate the forms, they learned other bases for responding that could be classified as specifiable error patterns. Children in the experimental group, having learned the preliminary circle-ellipse discrimination, were started at the upper end of the ellipse series, where it was impossible for them to discriminate the forms. The backup procedure returned them to an easier discrimination after they made errors. They made many errors and reversed down through the ellipse series. Eventually, most of the children reached a point in the ellipse series where they abandoned their systematic errors and began to make correct first choices; then they advanced upward through the program. All of the children advanced to ellipse sizes that were much larger than the ellipse size at the point of their furthest descent.

Journal of the experimental analysis of behavior, 1967 · doi:10.1901/jeab.1967.10-261