The use of a discrimination-training procedure to teach mand variability to children with autism.

Three preschoolers with autism took part. The team set two placemats on the table. Green mat meant 'say a new mand.' Red mat meant 'repeat the same mand.'

Scripts and a lag schedule taught the kids which mat needed variety. Later the scripts and lag rule were taken away to see if the children still varied their requests.

All three children quickly gave different mands on the green mat and stuck with one mand on the red mat. The skill stayed strong after supports were removed.

The children also showed the green-mand variety with a new peer, showing the learning traveled beyond the adult trainer.

Gardner et al. (2009) first used a lag schedule alone to boost vocal variety. Allen et al. (2016) kept the lag idea and added color cues plus script fading, making the method easier to use in busy classrooms.

Poppes et al. (2016) ran the same lag logic but targeted intraverbals instead of mands. Both studies found positive results, showing the tool works across different verbal operants.

Seaver et al. (2023) later swapped the placemats for concurrent schedules plus prompts. Their success confirms the core idea—differential reinforcement grows mand variety—while giving teachers a second setup to pick from.

You can cut repetitive mands without extra toys or complex tech. Place a green card in front of the child, require a new request, and reinforce. Swap to a red card when repetition is okay. Fade the cards once the child responds correctly for several days. Try it during snack, play, or transitions to build flexible communication that peers will enjoy.