Increasing response diversity in children with autism.

The team used a lag-3 schedule with kids with autism. The kids had to build three different block towers before earning a reward.

They could ask for help, but the main rule stayed: no repeats until three new shapes were made.

The children started making many new towers. The same blocks were on the table the whole time.

No extra toys were needed. Just the rule 'build something new' created more variety.

Gardner et al. (2009) did this first with sounds. They used lag-1 and showed it can make vocal play grow.

Jones et al. (2010) bumped the lag to three and moved it to block play. Same idea, new place.

Olin et al. (2020) later mixed lag-1 and lag-2 with picture cues for social questions. All three studies show: higher lag equals more variety.

Cohrs et al. (2017) added many examples before the lag. That combo works for social skills groups.

You can stretch flexible play without buying new items. Pick one toy set, set a lag-3 rule, and reinforce new shapes. It keeps therapy fresh and builds creativity in kids who like sameness.