The Development of a Motor-free Wechsler Intelligence ... · The Development of a Motor-free...
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The Development of a Motor-free Wechsler Intelligence Scale for Children – Fourth Edition – Short Form A. M. Piovesana 1 , S. Ross 1 , O. Lloyd 2 , & R. N. Boyd 1 1 Queensland Cerebral Palsy and Rehabilitation Research Centre, School of Medicine, The University of Queensland, Brisbane, Australia 2 Queensland Paediatric Rehabilitation Service, Children’s Health Queensland, South Brisbane,, Australia Objective: Traditional intellectual assessments have the potential to underestimate IQ in children with CP because they rely on fine motor movements to respond and complete tasks. Given intelligence assessments are often used to classify intellectual impairments and to determine eligibility for additional resources at school, government support, and access to rehabilitation programs, it is essential that assessments are not confounded by manual abilities. The objective was to develop a Motor-free (MF) Wechsler Intelligence Scale for Children – Fourth Edition (WISC-IV) Short-form (SF) that allows clinicians to estimate Full Scale Intelligence Quotients (FSIQ) in youth with Cerebral Palsy (CP) aged between 6-16 years old. Conclusion: Traditional intellectual assessments have the potential to underestimate IQ in children with CP because they rely on fine motor movements to respond and complete tasks (Sherwell et al., 2014; Sigurdardottir et al., 2008). Given intelligence assessments are often used to classify intellectual impairments and to determine eligibility for additional resources at school, government support, and access to rehabilitation programs, it is essential that assessments are not confounded by manual abilities. The Motor-free WISC-IV Short-form offers clinicians and researchers an alternative to measuring cognitive and intellectual abilities in children with fine motor impairments, especially children with CP. The short-form utilizes motor-free WISC-IV subtests to create verbal and perceptual composite scores, and can be used to estimate IQ. The WISC-IV Short-form takes approximately half the time to administer compared to the full WISC-IV and has demonstrated excellent and comparable reliabilities. For further information please contact Dr Adina Piovesana: [email protected] Wechsler, D. (2003). Wechsler Intelligence Scale for Children fourth edi6on: technical and interpreta6ve manual. San Antonio, TX: The Psychological Corpora@on. OlmMadden, T. (2008). A reliable approach to psychological assessment using cogni6ve tes6ng ba>eries. (Thesis (PhD/Research), University of Queensland. Sherwell, S., Reid, S. M., Reddihough, D. S., Wrennall, J., Ong, B., & StargaR, R. (2014). Measuring intellectual ability in children with cerebral palsy: Can we do beRer? Research in Developmental Disability, 35(10), 25582567. SigurdardoZr, S., EiriksdoZr, A., GunnarsdoZr, E., Meintema, M., ArnadoZr, U., & Vik, T. (2008). Cogni@ve profile in young Icelandic children with cerebral palsy. Developmental Medicine & Child Neurology, 50(5), 357362. Method: This study implemented the Reliable Approach to Psychological Testing (RAPT) algorithms developed by Olm-Madden (Olm-Madden, 2008) which integrates psychometric theory with the psychometric properties of standardised cognitive tests to generate normative tables and statistical analyses that are appropriate for the normative data for which it was derived. The RAPT algorithms allow clinicians and researchers to construct, analyse, and interpret a battery of cognitive tests specifically designed to address the individual needs of the client or population while ensuring the psychometric properties of the battery itself. The benefit in using these algorithms is that a battery can be constructed using the tests that demonstrate that highest psychometric properties (e.g. reliability) and clinical strengths (e.g. motor-free). Reliability and inter-correlations of five WISC-IV subtests that are motor-free (i.e. Arithmetic, Vocabulary, Information, Matrix Reasoning, and Picture Concepts) and the RAPT algorithms were used to develop look- up tables for three Short Form indices: Verbal Comprehension Index SF (VCI-SF); Perceptual Reasoning SF (PRI-SF) and a Motor-free Intelligence Quotient (MFIQ). Index level discrepancy tables were also developed enabling clinicians to compare visual and verbal abilities in children with CP, similar to those provided in the WISC-IV. Table 1: Comparison of the Alpha Reliability Coefficients for the Motor- free WISC-IV Short-form and the original WISC-IV Index Scale Motor-free WISC-IV SF WISC-IV Difference between the Alpha Reliability Coefficients VCI-SF/ VCI 0.93 0.94* 0.01 PRI-SF/ PRI 0.90 0.92* 0.02 MFIQ/FSIQ 0.96 0.97* 0.01 *Reliability coefficients based on the average coefficient calculated with Fisher’s z transformation (Wechsler, 2003, p.34) Results: • The VCI-SF had excellent reliability (r = 0.93) and is comparable to the original VCI of the WISC-IV (r = 0.94) • The reliability of PRI-SF ( r = 0.90) was comparable to WISC-IV PRI (r = 0.92) • The Motor-free Intelligence Quotient (MFIQ) also demonstrated excellent reliability (r = 0.96) and is comparable to FSIQ on the WISC-IV (0.96) • Clinicians and researchers are provided with user-friendly look-up tables, Index level discrepancy tables, and base rates displayed similar to those found in the WISC-IV manuals in order to interpret assessment results.
Transcript of The Development of a Motor-free Wechsler Intelligence ... · The Development of a Motor-free...
The Development of a Motor-free Wechsler Intelligence Scale for Children – Fourth Edition – Short Form
A. M. Piovesana1, S. Ross 1, O. Lloyd2, & R. N. Boyd1 1 Queensland Cerebral Palsy and Rehabilitation Research Centre, School of Medicine, The University of Queensland, Brisbane, Australia
2 Queensland Paediatric Rehabilitation Service, Children’s Health Queensland, South Brisbane,, Australia
Objective: Traditional intellectual assessments have the potential to underestimate IQ in children with CP because they rely on fine motor movements to respond and complete tasks. Given intelligence assessments are often used to classify intellectual impairments and to determine eligibility for additional resources at school, government support, and access to rehabilitation programs, it is essential that assessments are not confounded by manual abilities. The objective was to develop a Motor-free (MF) Wechsler Intelligence Scale for Children – Fourth Edition (WISC-IV) Short-form (SF) that allows clinicians to estimate Full Scale Intelligence Quotients (FSIQ) in youth with Cerebral Palsy (CP) aged between 6-16 years old.
Conclusion: Traditional intellectual assessments have the potential to underestimate IQ in children with CP because they rely on fine motor movements to respond and complete tasks (Sherwell et al., 2014; Sigurdardottir et al., 2008). Given intelligence assessments are often used to classify intellectual impairments and to determine eligibility for additional resources at school, government support, and access to rehabilitation programs, it is essential that assessments are not confounded by manual abilities. The Motor-free WISC-IV Short-form offers clinicians and researchers an alternative to measuring cognitive and intellectual abilities in children with fine motor impairments, especially children with CP. The short-form utilizes motor-free WISC-IV subtests to create verbal and perceptual composite scores, and can be used to estimate IQ. The WISC-IV Short-form takes approximately half the time to administer compared to the full WISC-IV and has demonstrated excellent and comparable reliabilities. For further information please contact Dr Adina Piovesana: [email protected] Wechsler, D. (2003). Wechsler Intelligence Scale for Children -‐ fourth edi6on: technical and interpreta6ve manual. San Antonio, TX: The Psychological Corpora@on. Olm-‐Madden, T. (2008). A reliable approach to psychological assessment using cogni6ve tes6ng ba>eries. (Thesis (PhD/Research), University of Queensland. Sherwell, S., Reid, S. M., Reddihough, D. S., Wrennall, J., Ong, B., & StargaR, R. (2014). Measuring intellectual ability in children with cerebral palsy: Can we do beRer? Research in Developmental Disability, 35(10), 2558-‐2567. SigurdardoZr, S., EiriksdoZr, A., GunnarsdoZr, E., Meintema, M., ArnadoZr, U., & Vik, T. (2008). Cogni@ve profile in young Icelandic children with cerebral palsy. Developmental Medicine & Child Neurology, 50(5), 357-‐362.
Method: This study implemented the Reliable Approach to Psychological Testing (RAPT) algorithms developed by Olm-Madden (Olm-Madden, 2008) which integrates psychometric theory with the psychometric properties of standardised cognitive tests to generate normative tables and statistical analyses that are appropriate for the normative data for which it was derived. The RAPT algorithms allow clinicians and researchers to construct, analyse, and interpret a battery of cognitive tests specifically designed to address the individual needs of the client or population while ensuring the psychometric properties of the battery itself. The benefit in using these algorithms is that a battery can be constructed using the tests that demonstrate that highest psychometric properties (e.g. reliability) and clinical strengths (e.g. motor-free). Reliability and inter-correlations of five WISC-IV subtests that are motor-free (i.e. Arithmetic, Vocabulary, Information, Matrix Reasoning, and Picture Concepts) and the RAPT algorithms were used to develop look-up tables for three Short Form indices: Verbal Comprehension Index SF (VCI-SF); Perceptual Reasoning SF (PRI-SF) and a Motor-free Intelligence Quotient (MFIQ). Index level discrepancy tables were also developed enabling clinicians to compare visual and verbal abilities in children with CP, similar to those provided in the WISC-IV.
Table 1: Comparison of the Alpha Reliability Coefficients for the Motor-free WISC-IV Short-form and the original WISC-IV
Index Scale
Motor-free WISC-IV SF
WISC-IV Difference between the Alpha Reliability
Coefficients
VCI-SF/VCI
0.93 0.94* 0.01
PRI-SF/PRI
0.90 0.92* 0.02
MFIQ/FSIQ 0.96 0.97* 0.01
*Reliability coefficients based on the average coefficient calculated with Fisher’s z transformation (Wechsler, 2003, p.34)
Results: • The VCI-SF had excellent reliability (r = 0.93)
and is comparable to the original VCI of the WISC-IV (r = 0.94)
• The reliability of PRI-SF (r = 0.90) was comparable to WISC-IV PRI (r = 0.92)
• The Motor-free Intelligence Quotient (MFIQ) also demonstrated excellent reliability (r = 0.96) and is comparable to FSIQ on the WISC-IV (0.96)
• Clinicians and researchers are provided with user-friendly look-up tables, Index level discrepancy tables, and base rates displayed similar to those found in the WISC-IV manuals in order to interpret assessment results.
