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Wechsler scales of intelligence are among the most frequently used individual measures of cognitive abilities world-wide (Georgas, van de Vijver, Weiss, & Saklofske, 2003; Lichtenberger & Kaufman, 2009) with several translations, adaptations, and standardizations.  However, evidence supporting the psychometric properties of Wechsler scores within low and middle income nations is lacking. It is important for test users to select instruments for which there is supporting psychometric evidence among members of the population with which they are used.  This symposium presents a collection of four papers detailing psychometric evaluations of Wechsler scales in cross-cultural contexts among low, middle, and high income nations.  The first paper reports independent structural analyses of the 15 WISC–IV^UK subtests with a sample of Irish children evaluated for learning difficulties.  Comparisons of Wechsler and CHC models and tests higher-order and bifactor structures are reported to better understand the nature of general intelligence.  The second paper examines the  adaptation and pilot testing of the Wechsler Preschool and Primary Scale of Intelligence-Third Edition (WPPSI-III) across sites in eight low- and middle-income nations, while highlighting relevant ITC guidelines.  Successful strategies are shared, and challenges and lessons are discussed.  The third paper presents the psychometric properties of an adapted form of the WPPSI-III: Escala de Inteligencia de Wechsler para Prescolar y Primaria–Third Edition (EIWPP-III; Wechsler, 2009), the Spanish-language form, among a cohort of low-income children in the Amazon basin in Peru.  The fourth paper provides evidence that supports the internal consistency and convergent validity of WPPSI-III scores among a sample of young children in rural Pakistan.  Lessons learned for adaptation and evaluation in highly disadvantaged contexts are shared.  This collection of papers helps shed light on the challenges of translating and adapting major tests of intelligence and evidence of validity of Wechsler scales across several cultural contexts and provide recommendations for interpretation.

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Paper 1: Structural Validity of the 15 WISC–IV^UK Subtests in an Irish Referral Sample
Gary Canivez, Marley Watkins, Trevor James, Kate James, & Rebecca Good

Abstract: A bifactor measurement model with the 10 core WISC–IV^UK subtests was supported in a large sample (N = 794) of Irish children referred for evaluation of learning difficulties.  Omega–hierarchical coefficients showed substantial reliability of the general intelligence dimension but inadequate reliability of the 4 group dimensions (VC, PR, WM, PS) and there was weak incremental prediction of achievement by the four WISC–IV^UK group factors (VC, PR, WM, PS) beyond the FSIQ.  No studies have been published examining the construct validity of the WISC–IV^UK using all 15 subtests that would allow for examination of rival CHC measurement models.  Accordingly, this study examined the latent factor structure of the 15 WISC–IV^UK subtests with data obtained from evaluations to assess learning difficulties of 162 Irish children to date.  Using CFA, one–four (Wechsler), and -five (CHC) oblique first-order factor models were examined along with Wechsler and CHC based higher–order and bifactor models.  Preliminary analyses found the oblique four–factor (Wechsler) and oblique five–factor (CHC) models fit better than one, two–oblique, or three–oblique factors, but did not meaningfully differ from each other in fit statistics (chi-square, CFI, RMSEA, AIC).  Because first–order factors were so highly correlated, hierarchical and bifactor structures required explication.  Meaningful differences between Wechsler and CHC based higher–order models were not observed although the Wechsler higher–order model had lower AIC value.  Bifactor models produced negative variance estimates for Digit Span and were judged inadequate.  Decomposed variance estimates from the Wechsler and CHC higher–order models showed dominance of general intelligence.  Omega hierarchical coefficients were substantial for the general dimension in both the Wechsler and CHC higher–order models but inadequate for the 4 Wechsler or 5 CHC group factors.  Implications for interpretation of WISC–IV^UK scores are discussed.

 

Paper 2: Using the Wechsler Preschool and Primary Scale of Intelligence-Third Edition Across Eight International Sites: Successes and Challenge
Laura Pendergast, Muneera Rasheed, Laura Murray-Kolb, Barbara Schaefer, Brittney Williams

Abstract: Guidelines from the International Test Commission (ITC) as well as many other professional organizations advise that test users should ensure that scores are valid among members of the populations with which they are used. These guidelines are important because cultural, linguistic, and other factors can systematically influence the way that test-takers understand and respond to test items (Chen, 2008) but present challenges for researchers and practitioners working in low- and middle-income nations where fewer measures of psychological functioning exist.

The Interactions of Malnutrition and Enteric Infections: Consequences for Child Health and Development (MAL-ED; Mal-ed.fnih.org) study is a multi-disciplinary, observational, prospective, clinical/field study conducted at 8 international sites in low- and middle-income nations: Dhaka, Bangladesh; Fortaleza, Brazil; Vellore, India; Bhaktapur, Nepal; Loreto, Peru; Naushahro Feroze, Pakistan; Venda, South Africa; and Haydom, Tanzania.  The sample consists of approximately 2,000 participants followed from birth through age five. The MAL-ED study aims to identify the periods during the first two years of life where malnutrition and specific enteric infections are associated with the greatest effect on growth and development.

In order to examine the ways in which malnutrition and enteric infection influence cognitive development, it is first necessary to measure child cognitive development across all eight sites. Thus, the Wechsler Preschool and Primary Scales – Third Edition (WPPSI-III) was adapted, piloted, and administered to participants at age five. Finally, psychometric analyses will be conducted and study-specific norms will be developed.

In this presentation, we will provide an in-depth review of the scale adaptation and pilot testing process while highlighting relevant ITC and other guidelines. We will share successful strategies and also discuss challenges and lessons learned in the process. Finally, we will review plans for final validation analyses and preliminary recommendations for ways in which the scores should (and should not) be used.

 

Paper 3: Factor Structure of Wechsler Preschool and Primary Scale of Intelligence-Third Edition- Spanish Form Scores among Rural, Preschool-aged Children in Peru
Barbara Schaefer, Abigail Crimmins, Margaret Kosek, Pablo Yori, Angel Orbe Vasquesz

Abstract: Adaptation of measures across culturally unique populations creates challenges in establishing validity of the resultant scores for use in the new population. The purpose of the study is to examine the psychometric properties of an adapted form of the Escala de Inteligencia de Wechsler para Prescolar y Primaria – Third Edition (EIWPP-III; Wechsler, 2009), the Spanish-language form of the Wechsler Preschool and Primary Scale of Intelligence (Third Edition), among a cohort of low-income children in the Amazon basin in Peru. Expectant mothers were recruited to the study through local health posts and lists of expectant mothers complied by researchers within the community. After the birth of the child, the newborn was screened for participation and informed consent was gathered from the parents/guardians. The research team followed children from birth through age 4, with cognitive assessments using the Bayley-III at 6, 15, and 24 months, and the EIWPP-III at 36 and 48 months. The sample (N = 155) is comprised of children who successfully completed the EIWPP-III at age 36 months, and a subsample (n = 78) of these children who completed the EIWPP-III at 48 months. Confirmatory factor analyses were applied to determine whether or not the factor structure of scores from the adapted EIWPP-III differ significantly from the factor structure of the scores from the original WPPSI-III. For each age level (i.e., 36 and 48 months), two potential models were proposed: (1) models identical to the factor structure demonstrated in the normative data, and (2) a one-factor model, such that all subtests will load on one general latent factor of intelligence. Results of these analyses will be presented.

 

Paper 4: Adaptation of the Wechsler Preschool and Primary Scale of Intelligence- III and Lessons Learned for Evaluating Intelligence in Preschool Aged Children in a Low Income Setting
Muneera Rasheed, Uzma Memon, Saima Siyal, Jelena Obradović, Aisha Yousafzai

Abstract: A review estimated that more than 200 million children under 5 years of age in low- and middle- income countries (LMIC) are not meeting their cognitive potential based on prevalence of proxy indicators of chronic malnutrition and poverty that are closely associated with cognitive development. A lack of appropriate indigenous cognitive measures in the LAMIC is the major challenge to cognitive measurement.  Therefore, standard measures of cognitive development developed in the West are often used in LAMIC administered by non-specialists. However, detailed methodology of adaptation to the content, training procedures and psychometric properties of the adapted measure are not reported which can support advancement of the cognitive development measurement in these countries.

The current study had two aims: to adapt the subtests of the Wechsler Preschool and Primary Scale of Intelligence-III (WPPSI-III) to assess cognitive abilities in young children in rural Pakistan using a systematic adaptation protocol and  to examine the sensitivity of the adapted WPPSI III by exploring the performance with different risk exposures.

A sample 1273 children at 4 years of age were administered the WPPSI III as part of the study. A systematic adaptation protocol for making culturally relevant changes for 4 year old children and training non-specialists for data collection followed by test of psychometric properties after completing data collection.  Internal consistency as indicated by Cronbach’s alpha of 0.91was high for the Full Scale intelligence Quotient (FSIQ) score. The FSIQ had significant associations with socioeconomic status (N=1237, r=.306**, p=0.000), maternal education (N=1237, r=.224**, p=0.000), home environment (N=1231, r=.318**, p=0.000) and child nutritional status (N=1222, r=.198, p=0.000).

These findings provide evidence that supports the internal consistency and convergent validity of WPPSI-III scores among young children in rural Pakistan. Lessons learned for adaptation and evaluation in highly disadvantaged contexts are shared.