Adaptation of Adaptive Behavior Assessment System (ABAS-II): Pilot study in Latvia Malgozata Rascevska, Sandra Sebre University of Latvia, Latvia Tampere, 24-28 July 2007 e-mail: email@example.com
Why was it decided to adapt ABAS-II in Latvia? • This instrument adaptation is realized within the broader project framework together with the WISC-IV and Child Behavior Checklist (CBC, Achenbach). These 3 instruments could provide Latvian school psychologists with high quality assessment methods to identify pupils’ main psychological problem in school setting regarding intelligence, adaptive behavior and clinical disturbances. • Only recently in Latvia do we have school psychologists with enough work experience (5 -10 years) who could engage in this project, and financial support for scientific research. In 2005 we have completed adaptation of the Woodcock-Johnson Cognitive Ability Test. • ABAS-II is instrument with high reliability and validity.
Introduction • The Adaptive Behavior Assessment System – Second Edition (ABAS-II) provides a comprehensive norm-referenced assessment of the adaptive skills of individuals ages birth to 89 years (Harrison & Oakland, 2003). It was created in USA, the publisher – “ Harcourt Assessment”. • The clinician can use the ABAS-II to diagnose and classify disabilities and disorders; identify an individual’s strengths and limitations (Harrison & Oakland, 2005). • The assessment of an individual is provided by multiple evaluators (parents, teachers, family members, the individual).
Introduction (continuation) • ABAS-II consists of 5 Forms: • Parent/Primary Caregiver Form (ages: 0-5) • Teacher/daycare Provider Form (ages: 2-5) • Parent Form (ages: 5-21) • Teacher Form (ages: 5-21) • Adult Form (ages: 16-89) • ABAS-II includes an assessment of overall adaptive functioning and the 10 adaptive skill areas specified by Diagnostic and Statistical Manual of Mental Disorders-Forth Edition – Text Revision (DSM-IV-TR) and American Association of Mental Retardation (AAMR) guidelines for diagnosis of mental retardation.
The purpose of this study • is to translate and culturally adapt the ABAS-II (Teacher and Parent Form) for Latvian school children and perform a pilot testing of the psychometric properties of the instruments. The guidelines recommended by the International Test Commission (2000) were followed using two independent forward and one back translation.
Method Participants • The first sample was matched to theUSA standardization sample of ABAS-II (see Table 1) and consisted of 168 students aged from 7 to 21 (age: M=11.87, SD=3.32, 50% female and 50% male) from Grade 1 to 12 in ten schools from different Latvian regions. This sample was divided in 6 age subsamples quantified almost accordingly to correspondent age group proportion of USA standardization sample of the ABAS-II (see Table 1). • The second sample consisted of 26 children with mild mental retardation (aged from 10 to 19, 38% female and 62% male). • The third sample (n=52) was drawn from the first sample and matched to the second sample.
Table 1. Latvian sample matched to USA standardization sample of ABAS-II Method * matched to average subsamples of Parent Form and Teacher Form in USA
Method (continuation) Instruments • Adaptive Behavior Assessment System – Second Edition (ABAS-II) (Harrison, Oakland, 2003): Parent Form (ages 5 - 21) and Teacher Form (ages 5 - 21) • Both Forms provide scores at three levels: • total score named General Adaptive Composite (GAC), • 3 adaptive domain scores (Conceptual, Social and Practical), • 10 skill areas scores (Communication, Functional Academics, Self-Direction, Social, Leisure, Community Use, Home/School Living, Health and Safety, Self-Care, and Work). • Parent Form consist of 232 items, but Teacher Form 193 items. Each subscale is composed of 15 to 22 items which are estimated with points from 0 to 3.
Method (continuation) Translation procedure The translation process was performed in four stages: • Two translators translated the test from English to Latvian language (M.Rascevska and S. Sebre) and modified it considering specifics of Latvian culture. Two items in Parent Form and three items in Teacher Form were changed fully and 17 items were changed partly with only one or two words (in general 8% items were changed in each Form). • Ten Latvian school psychologists participated in special training course about ABAS-II and practiced completion of ABAS-II Forms for some pupils from parent and teacher position. After this discussion some items and details of instruction were corrected.
Method (continuation) Translation procedure • The research group created additional 2 items for each skill area in case the conceptually original items would not show appropriate psychometric properties in the pilot study. New items were included in the test forms. • Latvian-English bilingual Pauls Legzdins (psychologist from Toronto, Canada) performed the back translation. After comparing together forward and back translation of ABAS-II three items were revised.
Method (continuation) Procedure of data gathering The Latvian instrument was administered to a pilot study sample. From three to six students from one class and their parents and teachers were asked voluntarily to participate in this study. Each parent and teacher received an envelope with the test form and could complete it during a week. The school psychologist explained to them how to complete the ABAS-II Parent or Teacher Form.
Method (continuation) Procedure of data analysis The statistical analyses were performed using SPSS version 15.0. All items in 10 skill areas (separately for Parent and Teacher form) were analysed from four aspects: 1) item difficulty (item mean), 2) item discrimination (corrected item-total correlation), 3) item factor loading in one factor model of skill area, 4) item one-way ANOVA by 6 age groups. For all 10 skill areas composite scores were calculated: 5) the internal consistency (Cronbach’s alpha), 6) one-way ANOVA by 6 age groups and Post Hoc tests, 7) confirmatory factor analysis - one and three principal component analysis with varimax rotation for ABAS-II domain structure testing.
Results Item analyses(Parent Form) • In the Latvian sample the majority of itemdifficulty indices (61%) were above the critical point 2.40. Only 39% items satisfied psychometric criteria (20%-80% from max point, see Table 2). • On the average item difficulty indices of skill areas were indicative that items were too easy, especially for Self-Care scale (M=2.77, SD=0.42), Communication scale (M= 2.64, SD=0.51), Heath and Safety scale (M=2.54, SD=0.62), Functional Academics scale (M=2.51, SD=0.71), Social scale (M=2.49, SD=0.57), and Leisure scale (M=2.42, SD=0.65).
Item analyses Table 2. Summary of items psychometric analyses in each skill area
Item analyses • Such results were not specific for the Latvian sample, similarresults had been in the standardization sample of the original ABAS-II, because mean scores of skill areas in the Latvia sample were lower than corresponding means in the USA sample (see Figure 1, 2). • Therefore, in further analyses difficulty index was not used as an essential psychometric index of items.
80 70 60 Mean of scale raw scores 50 40 30 7-8 9-10 11-12 13-14 15-16 17-21 Age group 57 60 62 63 65 67 Latvian sample 61 64 65,5 66,5 67,5 69,5 U.S. sample Figure 1. Means of Communication area for different age groups in Latvian and USA sample
70 60 Mean of scale raw scores 50 40 30 7-8 9-10 11-12 13-14 15-16 17-21 Age group 34 47 51 57 59 63 Latvian sample 33,5 42 49 54 57,5 60,5 U.S. sample Figure 2. Means of Community Use area for different age groups in Latvian and USA sample
Item analyses • Almost all items (98%) showed good discrimination indices (within theinterval: r= .20 to .80) • Most of the items (87%)manifested factor loadings above .40 (in general factors of skill areas), only 13% items showed lower factor loadings ( .21 to .39) than the critical point. • Only 64% of the items showed significant differences of mean scores (p< .05) among the 6 age groups (ANOVA for groups: 7-8 to 17-21 years old), partly certified age validity of ABAS-II items. But raw scores of skill area showed significant differences among age groups (p<.01) in one-way ANOVA in all skill areas.
Reliability The internal-consistency reliability (Cronbach’s alpha) for total scale of ABAS-II Latvian version was .98, for skill areas - above .84, and for 3 domains – above .92 (see Table 3). Table 3. Cronbach’s alphas for Latvian and USA sample of ABAS-II Parent Form * Harrison, P.L., Oakland, T. (2003). Adaptive Behavior Assessment System. Second Edition. Manual. San Antonio; The psychological Corporation. (pp.82)
Reliability (continuation) Cross-Form Consistency(Parent and Teacher Forms, ages 5-21). The correlation coefficients for the skills areas betweenthe Parent and Teacher Forms were significant r= .22 to .69 (p< .01), but lower than in the USA sample: r= .60 to .70 (see Table 5). Table 5.Form consistency between the Ratings of Parents and Teachers for ABAS-II in Latvian and US sample * see Harrison, P.L., Oakland, T. (2003). Adaptive Behavior Assessment System. Second Edition. Manual. San Antonio; The psychological Corporation. (pp.109))
Mean scores of skill areas in Latvian sample are slightly lower than USA sample correspondingly means (see Table 4, Figure 3) Latvian score mean in Skill area of ABAS - II M SD USA norm sample* 1. Communication 63.56 6.09 9 2. Community Use 50.38 12.62 11 3. Functional Academics 57.76 11.31 9 4. Home Living 52.07 11.13 8 5. Health and Safety 55.87 7.09 9 6. Leisure 53.34 7.43 9 7. Self - Care 66.48 5.54 8 8. Self - Direction 56.19 10.11 9 9. Social 57.89 7.20 8 10. Work 54.52 7.89 - Descriptive statistics for skill areas Table 4. Descriptive statistics for Latvian sample of ABAS-II Parents Form scaled * Scaled score for age 11:10, M=10 (Latvian sample age mean 11:10), Harrison, P.L., Oakland, T. (2003). Adaptive Behavior Assessment System. Second Edition. Manual. San Antonio; The psychological Corporation. (pp.220)
Mean 0 2 4 6 8 10 12 1. Communication 2. Community Use 3. Functional Academics 4. Home Living Skill area of ABAS-II 5. Health and Safety 6. Leisure 7. Self-Care 8.Self-Direction 9. Social Figure 3. Mean skill areascores of Latvian sample formulating in USA Scaled scores (Mean=10)
Each skill area shows different age discrimination ability (compared means of age groups), for example:
Intercorrelations Among skill Area Scores • The theoretical structure of the ABAS-II suggests that the skill area scores will be somewhat independent of one another and with low to moderate interrelations, and all skill area scores will show a higher correlation in their respective domain than with areas from another domain (Harrison, Oakland, 2003, pp. 115). • In the Latvian sample some intercorrelations of skill area scores (Self-direction and Functional Academics) were higher with skill area scores from other domains than within the same domain (see Table 6). • The correlations of skill area scores varied from .42 to .75 (not including Work area) in the Parent Form (in average closer than in USA sample)
Table 6. Pearson correlation coefficients among skill areas for ABAS-II Parents Form in Latviansample 8 9 8 9
Factorial validity • Both a one-factor and three-factor structural model for the ABAS-II Parent Form Latvian version was tested (according to models of the original ABAS-II) using principal component method with varimax rotation. • The results shown in Table 7 confirmed only a one-factor model, but not a three-factor model. • Seven skill areas belong to more than one factor. This could explain the closer corelations among skill areas in the Latvian sample than the USA sample.
Table 7. One and three factor structure of ABAS-II Parents Formin Latviansample
Clinical validity • The purpose of the clinical study was to demonstrate that the ABAS-II Latvian version could provide a valid assessment of adaptive skills for individuals with mild mental retardation • Control group was matched to clinical group (n=26). • The clinical group’s mean raw scores in 7 skill areas were significantly lower than those of the matched control group (see Table 8). There were not significant differences between these groups in Community Use and Home Living skill areas (accordingly to parents’report).
Table 8. T-test for ABAS-II skill areas between children with mild mental retardation and matched control group **p< .01, *p< .05
Figure 10.Means of ABAS-II Parents Form scales for group of children with mild mental retardation and matched control group
Discussion • Our study was focused on the adaptation of the ABAS-II to Latvian language. In this presentation mainly the results of the Parent Form adaptation were reported. • Item analyses using difficulty indices, discrimination indices, item factor loadings in one-factor model of skill area and age groups ANOVA showed that at least 13% items have to be corrected. Problem with item difficulty indices (sometimes items were too easy, especially in Communication scale) is not a specific characteristic for the Latvian sample, but it is characteristic of the original ABAS-II.
Discussion(continuation) • The results of the reliability analyses provide evidence for internal consistency of the instrument: Cronbach’s alphas were above .82 for all the domain and skill area scales. These values are comparable to those for the original ABAS-II (Harrison & Oakland, 2003). • The pattern of intercorrelations of the skill area scores indicates that there is a stronger linear association among them than in the USA sample, especially between Self-Direction and other skill areas.
Discussion(continuation) • Only the one-factor model of the ABAS-II (Latvian version) skill area scores was confirmed in confirmatory factor analyses, but not the three-factor model. It was different result from the original ABAS-II structure (Harrison & Oakland, 2003). • The findings also support clinical validity of ABAS-II Latvian version (in 7 of 9 skill areas) in children with mild retardation. In the USA sample the clinical group showed lower level scores in all skill areas (5-6 years old children were included in the USA sample but not in the Latvian sample).
Conclusion • ABAS-II Latvian version is with high internal consistency. • Approximately 13% items demand correction because they measure weakly correspondent construct of skill area. • ABAS-II Latvian version demonstrates only one-factor structure, not three-factor or domain structure. • There is necessity for deeper analysis of the factor structure of ABAS-II Latvian version to determine reasons of such differences. These differences involve higher correlations among Self-Direction, Functional Academics area scores and skill area scores from outside domains than within the same domain.
References American Educational Research Association, American psychological association, and National Council on Measurement in Education. (1999). Standards for educational and psychological testing. Washington, DC: American psychological Association. Harrison, P.L., & Oakland, T. (2003). Adaptive Behavior Assessment System . San Antonio, TX: The Psychological Corporation. Hambleton, R. K. (1994). Guidelines for adapting educational and psychological tests: A progress report. European Journal of Psychological Assessment. 10 (3), 229 – 244. Hambleton, R.K., Merenda, P.F., & Spielberger C.D. (Eds.) (2005). Adapting educational and psychological tests for cross-cultural assessment. Mahwah, New York: Lawrence Erlbaum Associates. Hambleton, R. K., & Patsula, L. (1999). Increasing the validity of adapted tests: Myths to be avoided and guidelines for improving test adaptation practices. Association of Test Publishers, JATT, Vol. 1, No 1, 1 – 30. ITC Test Adaptation Guidelines (2006).