1. Gilliam Autism Rating Scale Second Edition
Eric Rozenblat, M.A., BCBA
Caldwell College
Assessment Project

2. Overview Background of GARS II Changes from original GARS to GARS II
Peer-reviewed literature about GARS
Description/Administration of GARS II
Scoring of GARS II
Pros and Cons about GARS II
Recommended Usages

3. Background of GARS Originally published in 1995 (Gilliam, 1995)
Based on definition of autism in DSM IV and Autism Society of America (1994)
Reliable and valid standardized test
Goal of GARS
Tests for reliability
Tests for validity
Used in schools and clinics internationally

4. Background of GARS 56-items divided into 4 subscales
Stereotyped Behaviors
Communcation
Social Interaction
Developmental Disturbances
Autism Quotient Scores and probability of having autism
Below 69 = very low
70-79 = low
80-89 = below average
= average
= above average
= high
131+ = very high

5. Revisions from original GARS
Development Disturbances subscale converted into interview
Re-written items
Demographic characteristics
New norms created
Autism Index
Guidelines for scores
Discrete target behaviors
Instructional Objectives for Children Who Have Autism

6. South et al. (2002)
The purpose of the South et al. study investigated the validity of using the GARS (1st edition) for children with pre-exisisting diagnoses of autism.
Examined GARS data for 119 children
Results showed mean GARS IQ was 90.10
Developmental Disturbances subscale not coorelated
Limitation

7. Lecavalier (2005)
Purpose was to examine construct and diagnostic validity, interrater reliability, and effects of participant characteristics on GARS scores

8. Lecavalier (2005) Data collected from parents and teacher
29 school districts across Ohio
Children selected between 3-21 who receive educational services for ASD’s
Data collected from parents and teacher
Final analysis included two components
Possess minimal language skills, expressive language at or above 20-month level
Minimum raw score

9. Lecavilier (2005) Verify information Final sample:
Parents asked if their child had been diagnosed by physician or psychologist as having an ASD and…
Teachers reported students classification as noted in their IEP
Final sample:
284 students, 225 male, 47 female, 12 no gender
195 autism, 35 pre-k disability, 29 misc, 25 none

10. Lecavilier (2005) Results Three factor analysis for construct validity
Factor 1-Stereotyped Behavior
One item did not belong, 7 others did from 2 subscales
Factor 2-Communication
All but 3 within communication belonged
Factor 3-Social Interaction
No items coorelated
No statistical differences on three behavioral subscales
No statistical difference between teacher/parent ratings

11. Other References Eaves 2006-reliability and validity of GARS
Results supported use of GARS as screening tool

12. DSM-IV-TR
Important to consider Diagnostic Criteria of Autism in DSM-IV-TR
A total of six or more items from 1, 2, and 3 with at least 2 from 1 and one each from 2 and 3
Qualitative impairment in social interaction
Qualitiative impairment in communication
Restricted and repetitive stereotyped patterns of behavior

13. Description/Administration of GARS II
42 clearly stated items divided into three subscales
Parent Interview
Most current definitions
Normed scale on 1,107 representatives
Objective
5-10 min to administer

14. Description/Administration of GARS II
Three subscales with 14 items each
Stereotyped Behaviors
Example includes rocks back and forth
Communication
Example includes repeats words or phrases over and over
Social Interaction
Example includes avoids eye contact
Examiner/Rater Qualifications

15. Scoring Presentation
Tables A-1 and A-2

16. Normative Data
See table 4.1

17. Reliability and Validity
See back of test

18. GARS II and ABA
See Chapter 7 in Examiner Book and Instructional Objectives for Children Who Have Autism

19. PROS and CONS Pros Cons Easy to administer GARS II not enough to DX
Takes little time Anecdotal parent questionnaire
Good reliability Lack of peer-reviewed research on GARSII
Good validity Raters may be subjective
Easy to compute Examiner may not administer test on own
Relation to ABA Does not describe environmental contingencies
Direct Observation Examiner qualifications (need specialists in autism with license)
Easy to score
Uses DSM IV Definition
Large Normative Sample

20. Recommended Usages Eaves et al. (2006)
The analysis of the internal consistency of the GARS supported its use as a screening device
California Collaborative Work Group on Autism Spectrum Disorders (1997)
The Quality Standards Subcommittee of the American Academy of Neurology
The Child Neurology Center (Filipek et al. 2000)

21. Recommended Usages Recommended not as primary measure
Autism specialists
Interpret with skepticism

22. Questions

23. References
American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed., text rev.). Washington, DC: Author. Boggs, K.M., Gross, A.M., & Gohm, C.L. (2006). Validity of the Asperger Syndrome Diagnostic Scale. Journal of Developmental and Physical Disabilities, 18, Bruininks, R.H., Woodcock, R.W., Weatherman, R.F., & Hill, B.K. (1996). Scales of independent behavior-Revised: Manual. Boston: Riverside Publishing Company. California Departments of Education and Developmental Services Collaborative Work Group on Autism Spectrum Disorders. (1997). Best practices for designing and delivering effective programs for individuals with autistic spectrum disorders. Available online at Eaves, R.C., Woods-Groves, S., Williams Jr., T.O., & Fall, A.M. (2006). Reliability and validity of the pervasive developmental disorders rating scale and the gilliam autism rating scale. Education and Training in Developmental Disabilities, 41,

24. References
Filipek, P.A., Accardo, P.J., Baranek, G.T., Cook, E.H., Dawson, G. et al. (1999). The screening and diagnosis of autism spectrum disorders. Journal of Autism and Developmental Disorders, 29, Gilliam, J.E. (2006). Gilliam Autism Rating Scale. (2nd ed.). Austin, TX: PRO-ED. Gilliam, J.E. (1995). Gilliam Autism Rating Scale. Austin, TX: PRO-ED. Lecavalier, L. (2005). An evaluation of the gilliam autism rating scale. Journal of Autism and Developmental Disorders, 35, Lopez, B.R., Lincoln, A.J., Ozonoff, S., & Lai, Z. (2005). Examining the relationship between executive functions and restricted, repetitive symptoms of autistic disorder. Journal of Autism and Developmental Disorders, 35, South, M., Williams, B.J., McMahon, W.M., Owley, T., Filipek, P.A., Shernoff, E., Corsello, C., Lainhart, J.E., Landa, R., & Ozonoff, S. (2002). Utility of the gilliam autism rating scale in research and clinical populations. Journal of Autism and Developmental Disorders, 32, Walz, N.C. (2007). Parent reports of stereotyped behaviors, social interaction, and developmental disturbances in individuals with angelman syndrome. Journal of Autism and Developmental Disorders, 37,