Comparing massed-trial instruction, distributed-trial instruction, and task interspersal to teach tacts to children with autism spectrum disorders.

Whitehouse et al. (2014) tested three ways to run discrete-trial tact lessons for kids with autism. They pitted massed trials (many in a row), distributed trials (spread through the day), and task interspersal (mixing easy and hard tasks) against each other.

Each child got all three formats in an alternating pattern. The team tracked how fast new tacts were learned.

Massed trials won. Five of six children learned new tacts faster when trials were packed together. Distributed trials and task interspersal took longer to reach mastery.

Wilson et al. (2023) extends the same massed-trial package into parents’ homes via telehealth. Their caregivers ran dense tact trials online and kids still learned quickly, showing the massed format travels well.

Boudreau et al. (2015) looks like a contradiction at first. They found no speed difference between reinforcement schedules during tact training. The key is they held trial distribution constant while Whitehouse et al. (2014) varied it; schedules matter less than how tightly trials are grouped.

McGee et al. (2025) reminds us that order can matter too. They showed that placing tact training before intraverbal work can protect later learning from visual-memory hiccups. Combine tight massed trials with smart sequencing for an extra boost.

If you run tact programs, stack the trials back-to-back instead of sprinkling them across the session. You will likely see mastery in fewer days and free up time for new targets. The same massed format works at home over Zoom, so parents can copy the pace during homework.