Teaching janitorial skills to the mentally retarded: acquisition, generalization, and maintenance.

Six teens with moderate intellectual disability learned to clean a school restroom. The team broke the job into 181 tiny steps. They used two prompt styles: most-to-least help for 20 hard steps, least-to-most for 161 easy ones.

The study ran in a real school janitor closet. Researchers tracked each teen with a multiple-baseline design across participants.

All six students mastered every step. They cleaned a second restroom they had never seen. Skills stayed sharp weeks later with no extra training.

Ruser et al. (2007) extends this work. They swapped adult prompts for a handheld computer. Teens with moderate ID still learned vocational tasks and kept 100% accuracy for nine weeks. The device carried the prompt schedule so staff did not have to.

Pellegrino et al. (2020) also extends the idea. They kept the least-to-most prompt order but delivered it through Zoom to adults with ID. Mastery still happened in under 15 sessions. The prompt hierarchy travels from in-person to telehealth.

Varley et al. (1980) used the same multiple-baseline design for a different job. They taught interview skills instead of cleaning, but both studies show vocational skills generalize to new places and people.

You can teach long job chains fast by matching prompt style to step difficulty. Save most-to-least for tricky parts, least-to-most for the rest. Plan for generalization early: test in a new restroom, store, or kitchen right after mastery. If staff time is tight, try a handheld or telehealth prompt — later studies show they work just as well.