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

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

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

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

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

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

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

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

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

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

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

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

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

Normative Data See table 4.1

Reliability and Validity See back of test

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

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

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)

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

Questions

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.

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.