Instructive feedback embedded within group instruction for children diagnosed with autism spectrum disorder

Leaf and team ran group DTT sessions with nine kids who have autism. While teaching the main tact target, the therapist slipped in an extra comment like “And a calf is a baby cow.” No questions or prompts followed the add-on.

They used a multiple-baseline design across kids. Each child got the same direct teaching, but the bonus information showed up only after the child’s baseline ended.

Every child mastered the directly taught tacts. They also picked up the secondary facts and even some items that were only ever said to other kids.

No extra trials were needed. The free learning held for all nine participants.

Tullis et al. (2022) repeated the same trick and got the same result. Their kids learned brand-new verbal responses they were never asked to say, showing the effect works beyond tacts.

Syriopoulou-Delli et al. (2012) tested two error-correction styles in DTT and saw mixed results. Leaf’s group skipped error correction for the bonus items and still saw gains, hinting that instructive feedback can outrun some correction loops.

Tassé et al. (2013) found that straight tact training alone can spark untrained intraverbals. Leaf adds a twist: you can drop the extra info during group work and still get free learning without separate tact drills.

If you run group DTT, you can double the pay-off. Slide a quick fact after the correct response and move on. Kids absorb the bonus without extra time or trials. Try it next session: after a child labels “apple,” add “Apples grow on trees,” and keep the pace. Check later if they can tact the tree—you may find you just gained a free target.