PEAK Pre-Assessments: Preliminary Evidence Establishing Internal Consistency and Construct Validity

May et al. (2019) checked if the PEAK pre-assessment scores line up with IQ and daily-living scores. They gave the short PEAK tests to autistic children at one clinic. Then they compared the scores to full IQ tests and parent reports of adaptive skills.

The PEAK pre-assessment scores moved up and down with IQ and adaptive scores. Higher PEAK scores matched higher IQ scores. The test also gave steady results each time, showing it is internally consistent.

Moore et al. (2020) built on this work. They showed PEAK-PA, the practitioner version, predicts PEAK-DT performance faster than the parent version. Together the two papers say: use PEAK-PA when you want a quick, valid snapshot.

Diz et al. (2011) adds comfort. They tracked preschoolers with uneven development for three years and found IQ scores stayed stable. That stability supports trusting the IQ link May et al. found.

Lecavalier et al. (2006) used a similar method. They checked sleep items on the DASH-II against direct observation in severe ID. Both studies prove short sub-scales can hold up when you compare them to longer tools.

You can start a language program with a fifteen-minute PEAK-PA instead of a ninety-minute IQ battery. The score gives you a quick read on where the learner stands and helps pick PEAK lessons that match their level. Less testing time means more teaching time on Monday morning.