An Internal and Critical Review of the PEAK Relational Training System for Children with Autism and Related Intellectual Disabilities: 2014-2017.

Root et al. (2017) read every PEAK study published between 2014 and 2017. They looked at how well the curriculum teaches language and thinking skills to children with autism or intellectual disability.

The authors did not run new experiments. They simply summarized what exists and pointed out gaps.

The review says PEAK is promising, but thin. Only a handful of small studies exist. Most show kids learn the taught skills, yet long-term or real-world gains are rarely tracked.

No study compares PEAK head-to-head against older, proven tools like PECS.

Preston et al. (2009) and Alfuraih et al. (2024) show PECS quickly gives non-verbal children a way to request. PEAK aims for broader language, yet the review admits it lacks this level of evidence.

McCoy et al. (2019) found staff master PECS fast, but use fades without extra support. PEAK training data are even scarcer, so the same fade-out risk applies.

Koudys et al. (2025) later showed telehealth PECS training keeps parents and kids on track months later. PEAK has no similar caregiver-training model, leaving a practical gap the curriculum has yet to fill.

BCBAs now have two choices: a slim PEAK track that may build wider language, or a thick PECS track that reliably builds requests. Use PEAK modules to fill specific holes in relational language, but keep your trusted PECS or SGD program for daily requesting. Add caregiver coaching and long-term probes no matter which tool you pick.