Effectiveness of delayed feedback on the accuracy of teaching communicative gestures to individuals with severe mental retardation.

Lerman et al. (1995) watched four trainers teach adults with severe intellectual disability how to make simple gestures.

The trainers got no feedback during the lesson. After the session ended the researchers told them what they did right or wrong.

A multiple-baseline design showed whether this delayed feedback changed the way trainers taught the next day.

Delayed feedback worked. Trainer accuracy went up after each post-session review.

The adults with disability received clearer teaching and learned gestures faster once their trainers improved.

Guinness et al. (2024) and Aljadeff-Abergel et al. (2017) now say wait-time is old news. Their data show feedback given right before the next session beats feedback given after the last one.

The newer papers used college students and neurotypical adults, not clients with severe ID. The 1995 study proves that even late feedback still helps when staff work with very vulnerable learners.

Sorrell et al. (2025) and Snapp et al. (2024) keep the post-session idea alive by adding video. They show delayed video feedback lifts both teacher FA skills and cheerleader tumbling, so the delay itself is not dead—medium matters.

If you cannot give feedback until the end of the day, do it anyway. A quick five-minute review of today’s gesture trials will still sharpen tomorrow’s teaching. When you can, slide the feedback closer to the next session; the newer literature says that is faster. Either way, never stay silent—your staff and your learners with severe ID both win when you speak up, even if the bell already rang.