Post on 26-Dec-2015
Gilliam Autism Rating Scale Second Edition
Eric Rozenblat, M.A., BCBA
Caldwell College
Assessment Project
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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
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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
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– 90-110 = average– 111-120 = above average– 120-130 = high– 131+ = very high
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Revisions from original GARS
1. Development Disturbances subscale converted into interview
2. Re-written items
3. Demographic characteristics
4. New norms created
5. Autism Index
6. Guidelines for scores
7. Discrete target behaviors
8. Instructional Objectives for Children Who Have Autism
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
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Lecavalier (2005)
Purpose was to examine construct and diagnostic validity, interrater reliability, and effects of participant characteristics on GARS scores
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Lecavalier (2005)
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
Lecavilier (2005)
Verify information– 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
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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-CommunicationAll but 3 within communication belonged
– Factor 3-Social InteractionNo items coorelated
No statistical differences on three behavioral subscales No statistical difference between teacher/parent ratings
Other References
Eaves 2006-reliability and validity of GARS– Results supported use of GARS as screening tool
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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 31. Qualitative impairment in social interaction
2. Qualitiative impairment in communication
3. Restricted and repetitive stereotyped patterns of behavior
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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
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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
Scoring Presentation
Tables A-1 and A-2
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Normative Data
See table 4.1
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Reliability and Validity
See back of test
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GARS II and ABA
See Chapter 7 in Examiner Book and Instructional Objectives for Children Who Have Autism
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PROS and CONS
Pros ConsEasy 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 Sample19
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)
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Recommended Usages
Recommended not as primary measure
Autism specialists
Interpret with skepticism
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Questions
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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, 163-182.
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 www.feat.org.
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, 300-309.23
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, 439-484.
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,
795-805.
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, 445-460.
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, 593-599.
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, 940-947. 24