Reliability and Validity of the Diagnostic Instrument on Adaptive Behaviour: A New Instrument Measuring Adaptive Behaviour in People With Moderate, Severe or Profound Intellectual Disability

The team built a new tool called the DIAB. It measures daily living skills in adults with moderate, severe, or profound intellectual disability.

Seventy-three adults joined. Two raters watched each person cook, dress, and use money. They scored 77 micro-skills like “opens zipper” and “counts coins.”

The test was repeated after two weeks to check if scores stayed the same.

Inter-rater agreement was a large share. Test-retest agreement was a large share. Those numbers are excellent.

Scores lined up with the Vineland but showed no floor effect. Even the lowest functioning adults earned points for small steps.

Suhrheinrich et al. (2020) also proved a short scale can be reliable. Their 3-point fidelity checklist matched long trial-by-trial coding. Both studies tell us you can save time without losing accuracy.

Paff et al. (2019) introduced the EBP-COM to catch teacher practices. Like DIAB, it gives observers a clear rubric and strong numbers. Together they show new tools can beat older, clunkier ones.

Gandhi et al. (2022) used the BRIEF-2 and saw low scores for kids with ASD. That tool has a floor; many kids hit bottom. DIAB fixes the same problem for adaptive behavior in adults with ID.

If you serve adults with profound ID, you can now measure tiny gains. Use DIAB to show progress to funders, set micro-goals, and adjust teaching step size. No more “zero” rows on the Vineland.