Comparing the effects of massed and distributed practice on skill acquisition for children with autism.

The team worked with three children with autism. They wanted to know if spacing out teaching helps kids learn faster.

Each child got two kinds of practice. One day they had many trials back-to-back. Another day they had fewer trials spread across days. The skills were naming items, reading words, and answering questions.

They used an alternating-treatments design. This means they quickly switched the two formats and watched which one won.

Distributed practice won every time. When trials were spread over days, kids reached the mastery line sooner.

Massed practice, the cram style, took longer to hit the same goal. The difference showed up for all three verbal skills.

Thiessen et al. (2009) came first. They proved that new tutors can run DTT well after a short self-study. Nickerson et al. (2015) used that solid DTT method and asked the next question: how should we schedule the trials?

Murphy et al. (2019) used the same quick-switch design with autistic kids. They compared computer lessons to table work. Both papers show that the format, not just the content, changes learning speed.

Koldas et al. (2025) moved the story forward. They used spaced DTT to teach reciprocal naming during play. Their success adds a social twist to the original spacing rule.

You can start using this on Monday. Take the day’s trial target and split it across the week. Five trials today, five tomorrow, instead of ten right now. The child still gets the same dose, but mastery arrives faster. No new materials, no extra cost—just smarter timing.