The effects of relationship focused intervention on Korean parents and their young children with disabilities.

Kim et al. (2005) worked with Korean mothers of preschoolers with developmental delays. The team taught the moms responsive play skills through home visits, coaching, and short video clips of their own play.

Mothers met a coach once a week for three months. Each visit lasted about one hour. The coach praised what the mom already did well and showed one new skill, such as waiting for the child to lead or copying the child's sounds.

After three months, mothers in the program talked and played more in tune with their children. They waited longer, matched the child's pace, and used warmer voices.

The children also changed. They looked at mom more, shared toys, and took more turns during play. Moms who grew the most responsive had children who gained the most new interaction skills.

The result lines up with Einfeld et al. (1996), an earlier US study. That team switched parents from one-skill-at-a-time coaching to PRT-style pivotal training and saw happier dinner-time talks. Kim et al. (2005) shows the same parent-responsiveness lever works across cultures.

Lam et al. (2009) later ran a similar home program in Vietnam using the Portage Curriculum. They also beat a no-treatment group on adaptive skills after one year. Together the three studies form a chain: brief, culturally-tuned parent coaching keeps working in East and Southeast Asia.

Ingersoll et al. (2024) moved the model online. Their telehealth Project ImPACT raised parent strategy use first, then child language later. This 2024 RCT keeps the parent-first pathway Mee found in 2005, proving the link still holds when sessions happen on a screen.

You do not need a year-long clinic program to move the needle. A short, home-based package that shows moms their own video and gives one clear tip per visit can lift both parent and child interaction in twelve weeks. If you serve Korean families, copy the exact script. If you serve other groups, keep the core—video feedback plus praise for what parents already do well—and swap the language and toys. The chain of studies says the recipe travels.