Assessment & Research

Diagnostic assessment of Asperger's disorder: a review of five third-party rating scales.

Campbell (2005) · Journal of autism and developmental disorders 2005
★ The Verdict

KADI is the best of five Asperger checklists, yet every scale needs backup from stronger tools.

✓ Read this if BCBAs doing intake assessments for school-age or adult clients.
✗ Skip if Clinicians who only use ADOS-2 and ADI-R.

01Research in Context

01

What this study did

The author read every published paper on five Asperger rating scales.

He checked how well each scale really measures Asperger traits.

The review covers KADI, ASDS, GADS, ASAS, and KAQ.

02

What they found

KADI has the strongest numbers for reliability and validity.

All five scales still have weak spots.

None can separate Asperger from high-functioning autism with confidence.

03

How this fits with other research

Parks (1983) said the same thing 22 years earlier: autism scales look reliable but lack real validity.

Marie-Tan et al. (2021) later showed the French RAADS-R can work in adults, yet it still gives many false positives.

Together the papers tell one story: rating scales help screen, but you must follow up with interviews and observations.

04

Why it matters

Pick KADI first if you need an Asperger checklist.

Treat any score as a red flag, not a diagnosis.

Always pair the scale with ADOS-2 or ADI-R before you write the report.

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Add KADI to your intake packet, but schedule an ADOS-2 before you confirm any Asperger label.

02At a glance

Intervention
not applicable
Design
narrative review
Population
autism spectrum disorder
Finding
not reported

03Original abstract

Five rating scales for screening and detection of Asperger's Disorder, three commercially available and two research instruments, are evaluated with reference to psychometric criteria outlined by Bracken in 1987 (Journal of Psychoeducational Assessment, 4, 313). Reliability and validity data reported in examiner's manuals or published reports are reviewed. The scales included in the review are the Asperger Syndrome Diagnostic Scale (ASDS), Autism Spectrum Screening Questionnaire (ASSQ), Childhood Asperger Syndrome Test (CAST), Gilliam Asperger's Disorder Scale (GADS), and Krug Asperger's Disorder Index (KADI). All published rating scales demonstrated significant weaknesses, particularly in the use of questionable normative samples. Among the published instruments, the KADI appears to be the most sound in terms of reliability and validity. The research instruments present incomplete psychometric data to date, but hold promise as clinical instruments.

Journal of autism and developmental disorders, 2005 · doi:10.1007/s10803-004-1028-4