Search

The relationship between the Early Screening Profiles (ESP; Harrison, 1990) and the Differential Ability Scales (DAS; Elliott, 1990a) was studied. The participants were 94 (57 males, 37 females) at-risk preschoolers ranging in age from 3 years 6 months to 5 years 11 months (M= 4 years 7 months; SD= 6.3 months). The sample included 72 Caucasians, 21 African Americans, and one Hispanic. This study found that the DAS GCA (General Conceptual Ability) mean score was significantly lower than the ESP Total Screening mean score. However, a strong relationship (r= .78) was found between the ESP Total Screening and DAS GCA scores, indicating that the ESP is a good predictor of cognitive ability among at-risk preschoolers. © 2000 John Wiley & Sons, Inc.

The Differential Ability Scales (DAS) and the Woodcock-Johnson Tests of Cognitive Ability-Revised (WJ-R COG standard battery) were administered to 81 children referred for special education services evaluation. Both the General Conceptual Ability (GCA) and the Nonverbal Reasoning scores of the DAS were significantly lower than the WJ-R COG Broad Cognitive Ability-Standard score (BCA-STD). The DAS Verbal and Spatial Composite scores were not significantly different from the BCA-STD. Low to moderate correlations were found between related constructs on the two tests.

This study evaluated the criterion-related validity for the Speed of Processing (SP) factor of the Differential Ability Scales (DAS; Elliott, 1990). The SP factor is comprised of one subtest score (Speed of Information Processing) based on results from factor analyses. Participants were an epidemiological sample (N= 1,400) stratified, within age levels, in proportion to census data on demography (e.g., race, gender, parents' educational levels). From this cohort, groups with unusual SP strengths and SP weaknesses were identified using General Cognitive Ability (GCA) scores from the DAS as contrasts (i.e., SP>GCA and GCA>SP differences at a population prevalence < 5%). The SP>GCA group (n= 60) and the GCASP group (n = 60) were matched to respective controls (where each control n = 60) on the demographic variables listed above and GCAs. Each group and its control were compared across three norm-referenced measures of achievement and six teacher-rated indices of behavioral adjustment. Comparisons failed to show significant differences on any criterion variable. Results are discussed in the context of how well epidemiological samples evaluate the validity of ability profiles and the need for future research to use more representative measures of processing speed (i.e., those with two or more subtests contributing to the factor).

The Differential Ability Scales (DAS) is a relatively new and well-received measure of intelligence for children and youth ages 21/2 through 17. Although there is evidence to support the construct validity of the DAS, there is little evidence concerning construct bias in the DAS. The purpose of this research was to test for construct bias in the DAS for children from the three major ethnic groups, and across the entire age range of the DAS. We also sought to determine the nature of the constructs measured across these three groups. Both purposes were accomplished through hierarchical, multisample confirmatory factor analysis of DAS standardization data. The research also illustrates the use of this methodology to perform a comprehensive test of construct bias. Results suggest that the DAS measures the same constructs for all three ethnic groups across the four age levels studied; the DAS, therefore, shows no construct bias across groups. Furthermore, the hierarchical factor structure of the test is quite consistent with the DAS's actual structure, thus supporting the construct validity of the DAS. The DAS's Nonverbal reasoning cluster may be a good measure of fluid intelligence.

Horn's distinction between fluid intelligence (Gf) and visualization (Gv) was investigated with two Nonverbal Reasoning subtests from the Differential Ability Scales and three Simultaneous Processing subtests from the Kaufman Assessment Battery for Children. The sample comprised a predominantly Euro-American group of 57 normal boys and girls between the ages of 6 and 12 years. Principal factor analysis yielded clear-cut Gf and Gv dimensions. The Gf factor was composed both of Differential Ability Scales and Kaufman–ABC subtests, suggesting that the construct of simultaneous processing is not merely a measure of Gv, as some researchers have hypothesized, but also measures Horn's Gf fluid intelligence to a considerable extent.

This research evaluated the criterion-related validity of unusual subtest profiles from the Differential Ability Scales (Elliott, 1990). Three methods were used to identify unusual profiles: multiv...

The Differential Ability Scales (DAS) was administered to young children (ages 3 to 6) to determine the appropriateness of the instrument with children with linguistic differences. Specifically, the Special Nonverbal Composite (SNC) of the DAS was investigated for children with linguistic differences and children who speak English as their first language. The ability of the SNC to differentiate children with linguistic differences as opposed to more global developmental delays was also of interest. The children who participated in the study were grouped as: (a) no identified concern, English as primary language (control); (b) identified as having Specific Language Impairment (SLI); (c) identified as Deaf/Hearing Impaired (Deaf/HI); (d) identified as Developmentally Delayed (DD); or (e) no identified developmental concern, English as a Second Language/Limited English Proficiency (ESL/LEP). Children in the SLI, Deaf/HI, and DD groups had been identified previously by their school district, local Speech and Hearing Clinic, or other agency. Children in the ESL/LEP group were from a variety of cultural backgrounds and spoke minimal English. Results indicate that SNC scores obtained for children in the ESL/LEP group were comparable to those obtained by the control group. Children in the SLI and Deaf/HI groups obtained scores lower than those of the control and ESL/LEP groups; however, their scores were significantly higher than those obtained by the children in the DD group. Implications for the use of the SNC in the assessment of young children with linguistic differences are discussed.

The linear loadings of intelligence test composite scores on a general factor (g) have been investigated recently in factor analytic studies. Spearman's law of diminishing returns (SLODR), however, implies that the g loadings of test scores likely decrease in magnitude as g increases, or they are nonlinear. The purpose of this study was to (a) investigate whether the g loadings of composite scores from the Differential Ability Scales (2nd ed.) (DAS-II, C. D. Elliott, 2007a, Differential Ability Scales (2nd ed.). San Antonio, TX: Pearson) were nonlinear and (b) if they were nonlinear, to compare them with linear g loadings to demonstrate how SLODR alters the interpretation of these loadings. Linear and nonlinear confirmatory factor analysis (CFA) models were used to model Nonverbal Reasoning, Verbal Ability, Visual Spatial Ability, Working Memory, and Processing Speed composite scores in four age groups (5-6, 7-8, 9-13, and 14-17) from the DAS-II norming sample. The nonlinear CFA models provided better fit to the data than did the linear models. In support of SLODR, estimates obtained from the nonlinear CFAs indicated that g loadings decreased as g level increased. The nonlinear portion for the nonverbal reasoning loading, however, was not statistically significant across the age groups. Knowledge of general ability level informs composite score interpretation because g is less likely to produce differences, or is measured less, in those scores at higher g levels. One implication is that it may be more important to examine the pattern of specific abilities at higher general ability levels.

As part of a mandated three-year reevaluation, the Differential Ability Scales (DAS) was administered to 53 children identified as having a learning disability approximately 3 years after each had been administered the Wechsler Intelligence Scale for Children—Third Edition (WISC-III). The DAS's General Conceptual Ability score (GCA), and Verbal and Spatial Cluster scores were nonsignificantly different from the WISC-III's Full Scale, Verbal, and Performance scores. The Nonverbal Reasoning score of the DAS (a measure of Fluid intelligence not assessed by the WISC-III) was significantly different from both the Verbal and Performance scores. High correlations were found between the similar constructs on the two tests. Approximately 96% of the students obtaining a certain classification from the WISC-III obtained a comparable classification from the DAS. © 1996 John Wiley & Sons, Inc.

The ability profiles most representative of the school-age norm group for the Differential Ability Scales (DAS; Elliot, 1990a), an individually administered test of cognitive skills, are identified and described. The cognitive subtest profiles of the 2,400 children aged 6 to 17 years who comprise the DAS national sample were sorted based on their level, shape, and dispersion using multistage hierarchical cluster analyses with independent replications. Seven core profile types were discovered that adequately met established heuristic and statistical criteria, including acceptable internal cohesion, external isolation, replicability, short-term stability, and full coverage of the sample. Each profile type was described in terms of prevalence and constituent children's characteristics (i.e., overall differential ability, academic achievement, and distinguishing prevalence trends for age, sex, race/ethnicity, and parent education). Discussion showed how the typology provides clinicians and researchers with the necessary contrasts against which to evaluate claims regarding the distinctiveness and potential diagnostic and treatment utility of specific DAS profiles. Included are three methods for assessing the uniqueness of any DAS profile: two methods appropriate for research and one suited for clinical practice.

This article memorializes Colin D. Elliott (1937-2016). For 7 years, in his work as a school psychologist, Elliott studied the ability profiles of children with learning disabilities and the measurement of children's developmental stages. Subsequently, he trained school psychologists for over 20 years at the University of Manchester. In 1983, he made a major, enduring contribution to the field of psychometric assessment in both his home country and the wider field with the publication of the innovative British Ability Scales (BAS). An American version, the Differential Ability Scales (DAS), followed in 1990, and both versions of the test have been widely used and revised several times (BAS 2, BAS 3, and DAS-II). Many of his innovations in those tests have been adopted in other instruments. His other research and many publications focused on individual differences in children's temperament and personality and specific learning difficulties. Elliott moved to the United States in 1992 and was adjunct professor at the Gevirtz Graduate School of Education at the University of California, Santa Barbara. (PsycINFO Database Record

This study examined the performance characteristics of 83 school-identified learning-disabled (LD) children on the Differential Ability Scales (DAS). As a group, the children scored low on many subtests relative to normative data. Correlations between the DAS and archival Wechsler Intelligence Scale for Children-Revised (WISC-R) and achievement tests provided further evidence for DAS validity, although differences in the cognitive processes measured remain. Sixty percent showed a significant standard score discrepancy between the General Conceptual Ability (GCA) and at least one achievement test, based on the simple difference approach. Based on DAS ability-achievement discrepancy patterns, comparisons between more homogeneously defined groups yielded few differences that were independent of group definition criteria. The results from a cluster analysis (Ward's method) yielded two subgroups that differed in terms of their ability-achievement discrepancy. Numerical auditory-sequential recall (Recall of Digits) appeared to be equally problematic for the two subgroups. Overall, compared with previous DAS studies, fewer implications regarding cognitive processes underlying learning disability can be made with findings from this study. It remains unclear whether the cognitive characteristics measured by the DAS will facilitate or improve the educational diagnostic and intervention processes currently utilized with LD children.

The study explores the extent to which important demographic characteristics (age, gender, ethnicity, social class, national region, community size, and their interactions) are able to account for variation in children's cognitive ability, academic achievement, and social adjustment. For a representative national sample (N = 1,200) of children 5–17 years old, ability constructs (verbal, nonverbal, and spatial ability, and reading and numerical achievement) were assessed through the individually administered Differential Ability Scales. Adjustment constructs (attention-deficit hyperactive, solitary aggressive-provocative, solitary aggressive-impulsive, oppositional defiant, diffident, and avoidant) were assessed through teacher ratings with the Adjustment Scales for Children and Adolescents. Partialled canonical redundancy and regression analyses revealed that 18.9% of ability variation (assuming control for chronological age and social adjustment) could be accounted for by demographics, particularly social class and ethnicity. Only 5.5% of the variability in adjustment (with control for varied ability) related to demographic factors, mainly gender and age. The results are discussed in the context of recent trends to advocate the use of separate norms and comparative assessments for distinct demographic groups.

This study investigated the relationship between the Bracken Basic Concept Scale (BBCS) and the Differential Ability Scales (DAS) in a sample of 60 preschool children between the ages of 3 years 6 months, and 5 years 11 months from Indiana and Oklahoma. A high relationship (r = .80) was found between the BBCS Total Test score and the DAS General Conceptual Ability (GCA) score. This high relationship indicates that the two measures assess similar skills, but is not high enough to warrant substitution of one for the other. A strong correlation also was found between the School Readiness Composite on the BBCS and the DAS GCA.

Summary This article reports the conversion of one scale of the Differential Ability Scales into tactile form for use with the blind school‐age population. It explains the process of conversion and the decisions that were made, and discusses the findings and implications for the education and testing of the blind.

This chapter describes contemporary approaches to the assessment of cognitive and intellectual functioning. The origins of intelligence testing at the beginning of the twentieth century are briefly recounted. Six major intelligence tests are described in terms of their origins, theoretical underpinnings, standardization features and psychometric adequacy, and interpretive indices and applications. These tests include the Cognitive Assessment System, Differential Ability Scales, Kaufman Assessment Battery for Children, Stanford-Binet Intelligence Scale, Wechsler Intelligence Scales, and the Woodcock-Johnson Tests of Cognitive Abilities. It is argued that in order for the study and practice of intellectual assessment to achieve status as a mature clinical science, the field must meet four essential requirements: (1) a coherent foundational theory, from which testable principles and propositions may be derived, (2) a variety of measures, operationalizing the theories and serving the needs of special populations, (3) an applied diagnostic taxonomy, derived from and consistent with the theory and its measures, and (4) a compendium of change-oriented intervention techniques, aimed at modifying specific behaviors in a manner consistent with the theories. In spite of an abundance of theories and measures, the study of intelligence and its assessment has yet to realize its potential in terms of diagnosis and intervention. Keywords: cognitive; diagnosis; intelligence; IQ; Kaufman; Stanford-Binet; Wechsler

Despite widespread use of the Mullen Scales of Early Learning (MSEL; E. M. Mullen, 1995) as a cognitive test for children with autism spectrum disorders and other developmental disabilities, the instrument has not been independently validated for use in these populations. Convergent validity of the MSEL and the Differential Ability Scales (DAS; C. D. Elliott, 1990, 2007) was examined in 53 children with autism spectrum disorder and 19 children with nonspectrum diagnoses. Results showed good convergent validity with respect to nonverbal IQ (NVIQ), verbal IQ (VIQ), and NVIQ–VIQ profiles. These findings provide preliminary support for the practice of using MSEL age-equivalents to generate NVIQ and VIQ scores. Establishing convergent validity of cognitive tests is needed before IQs derived from different tests can be conceptualized as a uniform construct.

We previously reported that foetal valproate exposure impairs intelligence quotient. In this follow-up investigation, we examined dose-related effects of foetal antiepileptic drug exposure on verbal and non-verbal cognitive measures. This investigation is an ongoing prospective observational multi-centre study in the USA and UK, which has enrolled pregnant females with epilepsy on monotherapy from 1999 to 2004. The study seeks to determine if differential long-term neurodevelopmental effects exist across four commonly used drugs (carbamazepine, lamotrigine, phenytoin and valproate). This report compares verbal versus non-verbal cognitive outcomes in 216 children who completed testing at the age of three years. Verbal and non-verbal index scores were calculated from the Differential Ability Scales, Preschool Language Scale, Peabody Picture Vocabulary Test and Developmental Test of Visual-Motor Integration. Verbal abilities were lower than non-verbal in children exposed in utero to each drug. Preconceptional folate use was associated with higher verbal outcomes. Valproate was associated with poorer cognitive outcomes. Performance was negatively associated with valproate dose for both verbal and non-verbal domains and negatively associated with carbamazepine dose for verbal performance. No dose effects were seen for lamotrigine and phenytoin. Since foetal antiepileptic drug exposure is associated with lower verbal than non-verbal abilities, language may be particularly susceptible to foetal exposure. We hypothesize that foetal drug exposure may alter normal cerebral lateralization. Further, a dose-dependent relationship is present for both lower verbal and non-verbal abilities with valproate and for lower verbal abilities with carbamazepine. Preconceptional folate may improve cognitive outcomes. Additional research is needed to confirm these findings, extend the study to other drugs, define the risks associated with drug treatment for seizures in the neonates, and understand the underlying mechanisms.

The purpose of this study was to determine whether distinct subgroups of children with learning disabilities could be identified using a single, recently developed instrument—the Differential Ability Scales (DAS). Ward's method of cluster analysis was used to group 83 school-verified children with learning disabilities from the standardization sample. The following six subgroups were identified: (a) generalized, (b) high functioning, (c) normal, (d) underachievement, (e) borderline, and (f) dyseidetic. Not all subgroups displayed the expected discrepancy between intelligence and achievement associated with the current definitions of I.D. In subsequent discriminant analyses, both achievement and diagnostic subtests were necessary for accuracy in classification. This study provided evidence of the DAS's ability to diagnose the learning disabled differentially and provided distinct profiles for LD subgroups. Administration of the diagnostic subtests along with achievement subtests can provide the clinician with valuable diagnostic information for LD.

late-preterm (LPT) birth accounts for a majority of preterm deliveries and until recently was considered low risk for poor cognitive outcome. Previously, we reported deficits in complicated LPT (cLPT) preschoolers (neonatal intensive care unit [NICU]-admitted).to extend our prior study by comparing cognitive outcome in cLPT and uncomplicated LPT (uLPT; NICU non-admitted) preschoolers.single center retrospective cohort study of 118 LPT children born in 2004-2006 at 35-36 weeks of gestation; 90 cLPT and 28 uLPT, compared with 100 term-born (≥ 37 weeks of gestation and ≥ 2500 g) participants.a well-standardized measure of general conceptual ability (GCA), the Differential Ability Scales, Second Edition.cLPT participants had average mean performances but significantly poorer GCA, Nonverbal Reasoning, and Spatial scores than term-born children, and higher rates of Nonverbal Reasoning and Spatial impairment; uLPT did not differ from TERM. Combined LPT males were at eightfold greater risk than term-born males for nonverbal deficit, and at sevenfold greater risk for GCA impairment than LPT females.finding greater risk of cognitive deficit in those NICU-admitted due to clinical instability or birth weight2 kg compared with non-admitted preschoolers indicates that neonatal morbidities contribute to subtle cognitive deficits detectable at young age, with male gender an additive risk factor. LPT gestational age alone is an insufficient predictor of long-term neurocognitive outcome. Further study should elucidate salient etiologies for early emerging cognitive weaknesses and suggest appropriate interventions to prepare at-risk LPT preschoolers for elementary school entry.

The canonical relationship of the Verbal and Nonverbal clusters of the Differential Ability Scales Upper Preschool Level was studied. The two clusters share 45% of their variance. Independent interpretation of the Verbal and Nonverbal scales was supported.

This study examined the relationship between a cognitive abilities battery, the Differential Ability Scales (DAS), and academic achievement as a function of children's race. The subjects were 48 Asian-American and 1,731 white children, aged 6–17 years, from the DAS school-age standardization sample. Multiple regression was used to determine if the relationship between the DAS General Conceptual Ability cognitive composite and the Word Reading and Basic Number Skills achievement subtests of the DAS differed as a function of race. The regression slopes for the two groups were significantly different with Word Reading as the criterion. The Asian-American group possessed the steeper slope. Therefore, the degrees of systematic error in prediction increased as ability level increased. With Basic Number Skills as the dependent variable, slopes were equivalent but intercepts differed significantly. The results indicate that the majority white group scores were overpredicted on Basic Number Skills and Asian-Americans' scores were underpredicted when the common regression line was used.

This study contrasted the performance on the Differential Abilities Scales (DAS) of a carefully selected sample of reading-disabled children with a matched control group of children from the standardization sample. It was hypothesized that patterns on the DAS might be similar to those found on the Wechsler Intelligence Scale for Children-Revised and on the British Abilities Scales (BAS). The results suggest that reading-disabled children as a group do demonstrate a characteristic profile on the DAS. They score relatively poorly on the achievement tests and on two of the three diagnostic tests, Recall of Digits and Recall of Objects. The one exception to complete profile similarity between the DAS and the BAS was Speed of Information Processing. In the present study, low scores on Speed of Information Processing did not characterize the reading-disabled children as a whole but did characterize a subgroup of reading-disabled children. Clusters of reading-disabled children were generated from the data, and specific profiles of subgroups of children are presented.

The Differential Ability Scales (DAS) is one of the latest entries into the field of intelligence tests. Colin Elliot and the other developers of the DAS used the most current statistical procedures in an attempt to create a test that is psychometrically sound. They also sought to design subtests that measure a variety of separate and distinct areas of cognitive functioning. This article provides an overview of the instrument and a review of initial and current research. This research suggests that the developers of the DAS have succeeded in designing an instrument that has strong psychometric properties. There is, however, some concern about whether the subtests can be individually interpreted and about whether the factor structure will stand up to further research and clinical use. The use of current statistical procedures has given the DAS some improvements over other intelligence tests. The use of factor analysis enabled the DAS developers to include in the overall standard score only those subtests with high g loadings. The use of the Rasch model also allowed the DAS developers to incorporate adaptive testing for more efficient assessment. The development of extended norms allows the calculation of overall standard scores as low as 25, lower than other intelligence tests. The DAS appears to have promise as a useful addition to the field of intelligence testing and seems to be worthy of at least trial clinical and research use.

BACKGROUND: This study assessed the co-occurrence of cognitive problems and difficult temperament characteristics in children aged 3 to 5 years exhibiting aggressive behavior. METHODS: Thirty-one children with high ratings on the Aggressive Behavior subscale of the Achenbach Child Behavior Checklist or Teacher Report Form were recruited from a school district-based clinic. Cognitive ability and temperament were assessed with the Differential Ability Scales and the Carey Temperament Scales Behavioral Styles Questionnaire, respectively. Cluster analysis was applied to these variables. RESULTS: Three prominent groups of children sharing cognitive and temperament characteristics emerged. The first, comprising 41.9% of the sample, demonstrated low adaptability, low persistence, high activity, negative mood, and low rhythmicity, along with borderline-deficient cognitive scores. The second (38.7%) demonstrated low adaptability, low persistence, high activity, and negative mood, along with average cognitive scores. The third (19.4%) demonstrated essentially midrange temperament characteristics and average cognitive scores. All 3 groups shared temperamental tendencies toward a higher threshold of response. Most children in the sample also had significant sleep disturbances (54.5%), other health problems (63.6%), and/or suspected developmental problems (54.5%). CONCLUSIONS: The widespread presence of sleep, health, cognitive, temperament, and developmental problems in this sample supports the involvement of medical and developmental health experts in teams evaluating young children who present with high levels of aggressive behavior. The diverse nature of cognitive-temperament profiles in this sample also suggests a need to assess cognitive ability and temperament in young, aggressive children to provide individualized interventions. Language: en

The Differential Ability Scales (DAS) is a scale developed in the British empirical tradition and is purported to be useful in making educational decisions for children. This reaction focuses on and questions the DAS factor structure, the developmental theme of differentiation of abilities, and the role of the achievement subtests in the model of human abilities espoused in the DAS. The reaction concludes with a discussion of five areas of practical concern. These areas of concern are framed as questions: the racial differences question, the classification/diagnostic utility question, the ability-achievement discrepancy question, the profile development and use question, and the treatment validity question. Significant information relative to each of these questions is needed for the DAS before consumers can use the instrument meaningfully.

The purposes of this research were, first, to determine whether the varied tests contained in the Differential Ability Scales (DAS) measure the same constructs across its wide range, and, second, to determine what constructs and abilities are being measured by this new test. Confirmatory analysis was performed on the standardization data of the DAS using the LISREL 7 computer program. The first set of analyses, which included statistical comparisons of covariance matrices and first-order confirmatory factor analyses, suggested that the constructs measured by the DAS are quite consistent across overlapping age ranges. The second set — hierarchical confirmatory factor analyses — suggested that the DAS first provides a good measure of g, general intelligence. Also, the DAS appears to measure verbal ability and nonverbal reasoning skills.

The nature and the structure of children's abilities are considered in the light of evidence from the Differential Ability Scales (DAS), a newly published, individually administered cognitive test battery for children age 2 years 6 months through 17 years 11 months. The DAS was developed primarily to assess children's cognitive profiles. Evidence is presented on its relatively high levels of reliable specific variance (a requirement for identifying reliable intertest differences in a profile). The DAS cognitive battery also yields a number of focused composite scores: a measure of psychometric g, called General Conceptual Ability (GCA) and measures of Verbal and Nonverbal Ability at the preschool level, and of Verbal, Nonverbal Reasoning and Spatial Ability at the school-age level. The case is argued against the use of terms “intelligence” and “IQ” in describing children's abilities, and evidence on the factorial structure of the DAS is presented through both confirmatory and exploratory factor analyses.

Publisher Summary Mental retardation is a categorization for a heterogeneous group of individuals with concurrent deficits in intellectual and adaptive functioning. Mental retardation is a deviation in development that may increase the risk of mental disorder and be accompanied by medical issues. The combination of developmental, medical, and psychiatric factors makes treatment complicated. The chapter discusses various intelligence tests used in the assessment and diagnosis of mental retardation. These tests include the Bayley Scales of Infant Development, Second Edition, the Bayley Scales of Infant and Toddler Development, Third Edition, the Differential Ability Scales (DAS), the McCarthy Scales of Children's Abilities, the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III), the Wechsler Intelligence Scale for Children-Revised (WISC-IV), the Wechsler Adult Intelligence Scale, Third Edition (WAIS-III), the Stanford-Binet Intelligence Scales, (SB5), the original Leiter International Performance Scale, and the Leiter International Performance Scale-Revised. Measures of intelligence play a crucial role in the assessment, diagnosis, and treatment of children and adolescents with mental retardation. Different tests emphasize various elements of the construct of intelligence. Awareness of the range of available tests allows using multiple assessment tools to derive the most accurate information regarding an individual's cognitive and adaptive ability. Adequate training, practice, and clinical supervision are the mainstays of competency standards for intelligence testing when confronted with the complex task of differentially diagnosing mental retardation from a host of similarly appearing developmental disorders and learning disabilities.

Objective. There are limited data relating folate nutritional status of mothers during pregnancy to mental and psychomotor development of their offspring. Using an existing data set from a study on the effect of prenatal zinc supplementation on child neurodevelopment, we evaluated the association between folate nutritional status of mothers during pregnancy and neurodevelopment of their children. Methods. Maternal blood folate and total homocysteine (tHcy) concentrations were measured at 19, 26, and 37 weeks of gestation. At a mean of 5.3 years of age, 355 black children with low-socioeconomic background were given 6 tests: Differential Ability Scales, Visual and Auditory Sequential Memory, Knox Cube Test, Gross Motor Scale, and Grooved Pegboard. The scores of the tests between the 2 groups of mothers with poor versus adequate folate nutritional status classified by blood folate or tHcy concentrations were compared. Results. There were no differences in the test scores of neurodevelopment between the 2 groups. Conclusion. Folate nutritional status of mothers in the later half of pregnancy assessed by plasma and erythrocyte folate and plasma tHcy concentrations had no impact on neurodevelopment of their children at age 5. It is unknown whether our findings in a low-socioeconomic population can be readily extrapolated to other populations.

The Differential Ability Scales (DAS; Elliott, 1990c) is a comprehensive battery of cognitive and achievement tests that are designed for children and adolescents between the ages of 2 1/2 and 17 years. The DAS is a revision and U.S. adaptation of the British Ability Scales (BAS; Elliott, Murray, & Pearson, 1979). There were, however, several changes made in the DAS from its progenitor. In addition to the collection of the U.S. normative sample, several new subtests were developed and a standard “core” battery was created. The DAS Cognitive Battery has both a preschool level (see Chapter 15) and a schoolage level. For school-aged children, there are also reading, mathematics, and spelling achievement tests that are described primarily as “screeners.” All of these measures were normed on the same sample to make the comparison of cognitive and achievement domains more appropriate (see Chapter 14).

The effects of sleep-disordered breathing (SDB) on neurobehavioral function were examined in two matched groups of children from the general population. Thirty-five children with polysomnographically confirmed SDB were matched for ethnicity, age, gender, maternal educational attainment, and maternal smoking, to healthy children with no evidence of SDB. Children with SDB had significantly lower mean scores on the Differential Ability Scales for General Conceptual Ability (similar to IQ) and for the Non-verbal Cluster. On the neuropsychology assessment battery (NEPSY), children with SDB scored significantly lower than the control group on the attention/executive function domain and two subtests within that domain, one measuring visual attention and the other executive function. In addition, children with SDB scored significantly lower than the controls on one subtest from the NEPSY language domain: Phonological Processing. This subtest measures phonological awareness, a skill that is critical for learning to read. No differences in behavior, as measured by the Child Behavior Checklist (CBCL) or the Conners' Parent Rating Scale, were found between the two groups. Using a novel algorithm to assess sleep pressure, we found that children with SDB were significantly sleepier than controls. Furthermore, total arousal index was negatively correlated with neurocognitive abilities, suggesting a role for sleep fragmentation in pediatric SDB-induced cognitive dysfunction.

Background— Changes in neurocognitive function after cardiopulmonary bypass (CPB) are difficult to assess in children with congenital cardiovascular malformations in part because identification of a suitable control group of children is difficult. Methods and Results— We evaluated neurocognitive function in subjects aged 3 to 17 years both before and after surgical repair of an atrial septal defect (ASD). Eighteen subjects underwent testing within a median of 3 days (range, 1 to 27) before surgery and 5.8 months (range, 5.5 to 9) after surgery. The Differential Ability Scales was administered to subjects in a single testing session. All subjects were considered to be healthy, and they had no activity limitations. The mean General Conceptual Ability (GCA) scores (analogous to IQ) for the group were in the normal range before and after ASD repair. No significant difference was detected between the GCA scores before and after surgery. The GCA score was 90.8±18.6 before surgery and 93.1±16.3 after surgery. Conclusions— Use of CPB was not associated with changes in cognitive function in our subjects who underwent repair of an ASD.

The validity of the Differential Ability Scales (DAS; Elliott, 1990) in predicting attention disorders in school-aged children was examined. The participants were 40 children diagnosed with attention deficit/ hyperactivity disorder (ADHD) and 40 normal children between 7 and 12 years of age. Comorbidity was controlled by excluding children with ADHD who had a concurrent DSM-IV diagnosis such as reading disability, learning disability, mood disorder, or behavioral disorder. In addition, groups did not differ significantly by sex, age, racial/ethnic identification, or parental educational level. A stepwise discriminant analysis indicated the DAS correctly classified 72.5% of the total sample when either the Sequential and Quantitative Reasoning subtest or the Recall of Digits subtest was used to predict group membership. In general, the DAS core subtests were found to be good measures of cognitive ability in children classified with ADHD and did not appear to be influenced by attention problems.

The relevance of IQ to the etiology and symptomatic expression of autism remains unclear. Although approximately three-quarters of individuals with autism have below-average IQ (< 70), autism can occur with equal severity in individuals of average and above-average IQ. While the finding that IQ can vary widely between identical twins with autism (Le Couteur et al., 1996) would also suggest that it is not a useful marker of genetic subgroup differences in autism, there is nonetheless evidence from large-scale behavioral genetic studies (Bolton et al., 1994; Fein et al., 1999; Szatmari et al., 2000) that IQ broadly defined (e.g., high versus low Verbal or Full Scale IQ) may index etiological heterogeneity and provide a basis for subtyping in autism. In addition to ongoing attempts to elucidate the complex relationship of general intelligence, and particularly of mental retardation, to autism (Bailey, Phillips, & Rutter, 1996), there has also been longstanding interest in the uneven intellectual abilities of individuals with autism. One question has been whether routinely administered IQ tests reveal any consistent pattern of cognitive strengths and weaknesses in autism. A Wechsler (1991, 1997) IQ profile with Verbal IQ (VIQ) depressed relative to Performance IQ (PIQ) and peak subtest score on Block Design (Happe, 1994; Lincoln, Allen, & Kilman, 1995) has traditionally been associated with autism and has even been suggested as a possible diagnostic aid (Lincoln, Courshesne, Kilman, Elmasian, & Allen, 1988). Although a recent meta-analytic review of 23 published studies (Lincoln, Courchesne, Allen, Hanson, & Ene, 1998) confirmed that VIQ is generally lower than PIQ in autism, a VIQ < PIQ profile has not been found consistently across studies (see review by Siegel, Minshew, & Goldstein, 1996). Some authors (Rumsey, 1992; Siegel et al., 1996) have attempted to explain these inconsistent findings by proposing that the difference between Verbal and Performance IQ in autism depends on the severity of impairment and diminishes as intellectual ability approaches the normal range. Yet, a VIQ < PIQ profile has been reported in several studies of high-functioning individuals with autism (see reviews by Lincoln et al., 1998; Siegel et al., 1996). It has also been suggested that the difference between Verbal and Performance IQ lessens with age and associated improvements in language functioning, at least among higher-functioning individuals with autism (Lincoln et al., 1998). This hypothesis has been difficult to evaluate because most studies have included individuals spanning a wide range of ages, and very few studies have provided the opportunity to compare developmental differences between younger and older children. VIQ–PIQ discrepancies have also played a prominent role in efforts to define Asperger syndrome as distinct from autism. Klin, Volkmar, Sparrow, Cicchetti, and Rourke (1995) demonstrated a VIQ > PIQ discrepancy among a sample of individuals diagnosed with Asperger syndrome, opposite to the pattern typically found in autism. However, subsequent studies (Manjiova & Prior, 2000; Ozonoff, South, & Miller, 2000) have failed to differentiate Asperger syndrome from autism on the basis of Wechsler IQ profiles. These inconsistent findings may reflect differences in the way Asperger syndrome was diagnosed. The Klin et al. study used the most stringent criteria, requiring a circumscribed interest and motor clumsiness for inclusion in their Asperger group. It is possible that these specific criteria selected for individuals with a VIQ > PIQ profile, as the development of circumscribed interests is likely to be mediated by verbal skills, and motor problems might be expected to be associated with deficits in PIQ. The problem of circularity in attempts to provide external validation for the distinction between autism and Asperger syndrome has been well recognized (e.g., Klin & Volkmar, 1997; Volkmar & Klin, 2001). Questions of their broader nosological value aside, analyses of cognitive profiles within autism have suffered from two major limitations. First, emphasis on identifying a prototypical cognitive profile has been at the expense of considering the possibility of more than one cognitive profile in autism. At a conceptual level, recent advances in genetics and the understanding of autism as a complex disorder allow for the possibility of genetically meaningful variation in the cognitive phenotype of autism, which could potentially account for variation in the behavioral expression of autism. Yet, little attention has been paid to individual differences in cognitive profiles in autism. Particularly in the case of VIQ–PIQ differences, the report of group means for autistic samples could have the effect of ‘averaging out’ significant individual discrepancies that actually occur in both directions. The second limitation concerns the usefulness of Wechsler subscale discrepancies for characterizing cognitive profiles in autism. Individuals with autism have frequently been reported to exhibit a characteristic pattern of unevenness in the subtest scores from which Wechsler Verbal and Performance IQs are derived (Happe, 1994; Siegel et al., 1996). For example, Block Design, a measure of visuospatial constructional ability, reliably yields the highest Wechsler subtest score in autism. In contrast, Picture Arrangement, another Performance subtest, but one which requires social-inductive reasoning, yields one of the lowest subtest scores on the Wechsler scales. Factor analysis has shown that Picture Arrangement and Block Design are weakly correlated and measure distinct abilities in individuals with autism (Lincoln et al., 1988). Characteristic patterns of scatter are also found on the Wechsler Verbal scale. For example, Digit Span is regularly reported to be a relative strength on the Wechsler scales. Findings such as these raise questions about the interpretability of VIQ and PIQ scores in autism, and of any discrepancy that is (or is not) found between these scores. In the present study, we addressed two main issues. The first was whether children with autism exhibit characteristic patterns of unevenness in their cognitive abilities and, if so, whether such patterns or profiles differ as a function of age or overall ability. To answer these questions, we assessed the cognitive abilities of a large sample of children with autism using the Differential Ability Scales (DAS; Elliott, 1991), a revised version of the British Ability Scales (Elliott, Murray, & Pearson, 1979). The DAS is comprised of a Preschool and a School-Age battery. Each battery consists of only six core subtests, selected for their high loadings on psychometric g, but with sufficient specific variance to support separate cluster scores. The DAS factor structure and corresponding cluster scores are in accord with current models of human intelligence (Carroll, 1993; Mackintosh, 1998). They include Verbal and Nonverbal ability, the latter of which is further differentiated into Nonverbal Reasoning and Spatial ability in the School-Age battery. The DAS thus distinguishes between nonverbal subtests that primarily measure visual-spatial organization from nonverbal subtests that primarily measure inductive reasoning abilities.1 This is in contrast to the Wechsler system, which subsumes similarly divergent nonverbal subtests under its Performance subscale (Elliot, 1990). The second issue was whether different cognitive profiles in autism are associated with differences in core symptomatology. To address this issue, we assessed children’s social and communicative functioning using the Autism Diagnostic Observation Schedule (ADOS; Lord, Rutter, DiLavore, & Risi, 1999). The ADOS is a semi-structured, interactive observation scale that provides quantitative ratings of communicative and social behaviors corresponding to DSM-IV (APA, 1994) and ICD-10 (WHO, 1993) criteria for autism. The summary ratings from the ADOS allowed us to relate children’s neurocognitive profiles to quantitative measures of symptom severity in both the communication and social domains. This approach provided a way of potentially accounting for empirically defined phenotypic variance in autism while avoiding the methodological pitfalls involved in using a priori definitions, such as in recent attempts to differentiate Asperger syndrome from autism.

Preface Alan S. Kaufman and Nadeen L. Kaufman Part I. History and Tradition: 1. History lessons Margaret Jo Shepherd 2. The Wechsler intelligence scales Gary Groth-Marnat Part II. Alternative Cognitive Approaches to Learning Disabilities Assessment and Remediation: 3. Applications of the Woodcock-Johnson tests of cognitive ability - revised (WJ-R) to the diagnosis of learning disabilities Nancy Mather and Richard W. Woodcock 4. The Kaufman tests - K-ABC and KAIT Elizabeth O. Lichtenberger 5. Using the cognitive assessment system with learning disabled children Jack A. Naglieri 6. Application of the British Ability Scales (BAS II) and Differential Ability Scales (DAS) for the assessment of specific learning disabilities Colin D. Elliott 7. Is dynamic assessment compatible with the psychometric model? Reuven Feuerstein and Raphael S. Feuerstein 8. Multi-perspective, clinical-educational assessments of language disorders Elisabeth H. Wiig Part III. Neuropsychological Approaches to Learning Disabilities Assessment and Remediation: 9. Learning disabilities and their neurological foundations, theories, and subtypes Otfried Spreen 10. The Halstead-Reitan Neuropsychological Test Battery: research findings and clinical application Ralph M. Reitan and Deborah Wolfson 11. Developmental assessment of neurological function with the aid of the NEPSY Marit Korkman, Sarah L. Kemp and Ursula Kirk 12. Clinical neuropsychological assessment of child and adolescent memory with the WRAML, TOMAL, and CVLT-C Erin D. Bigler and Wayne V. Adams Part IV. Integration and Summation: 13. Assessment of specific learning disabilities in the new millennium: issues, conflicts, and controversies Alan S. Kaufman and Nadeen L. Kaufman Index.

Introduction and overview Two decades have passed since what was then a new test battery — the British Ability Scales (BAS; Elliott, Murray, & Pearson, 1979) — was introduced to the stable of tests for assessing cognitive abilities in children. The battery has since been further developed, resulting in the publication of the Differential Ability Scales (DAS; Elliott, 1990a) and the British Ability Scales, Second Edition (BAS II; Elliott, 1997a), which have achieved widespread acceptance and popularity in the USA and UK, respectively. The BAS II and DAS represent an advance in cognitive assessment. In a review of the original BAS, Embretson (1985) stated: ‘The BAS is an individual intelligence test with greater scope and psychometric sophistication than the major American individual tests. The test development procedures and norms are laudatory’ (p. 232). In another review, Wright and Stone (1985) stated that the BAS ‘is a significant advance in mental measurement … Its form and function are a model for contemporary test builders and a preview of the future of test construction’ (p. 232). Kamphaus (1993), in reviewing the DAS, wrote: ‘There is every indication that the developers of the DAS erred in the direction of quality at every turn. The manual is extraordinarily thorough, the psychometric properties are strong, and the test materials are of high quality’ (pp. 320–1).

This paper introduces the School-Years Screening Test for Evaluation of Mental Status (SYSTEMS). It was designed to be used by neurologists, pediatricians, and other health professionals assessing children with suspected cognitive problems or changes. SYSTEMS was initially based on the adult Mini-Mental State Examination developed by Folstein, Folstein, and McHugh in 1975. SYSTEMS is a 7- to 12-minute, one-on-one interview test containing 46 items for use in children between 5 and 12 years of age. Although a full diagnosis cannot be made, the results do provide an indication of whether to send a child for further detailed cognitive assessment. The development of SYSTEMS comprised seven studies with a total of 1207 children involved from Sydney primary schools and neurology clinics of the New Children's Hospital, Westmead, New South Wales, Australia. All children were administered the SYSTEMS. Some of the children also were administered the Stanford-Binet Intelligence Test, 4th edition, or the Differential Ability Scales. Results showed that the SYSTEMS was internally consistent, unbiased by sex, socioeconomic indicators, or language groups; discriminated well by age; and strongly correlated (r = 0.88) with mental age. No significant differences in results obtained by two trained administrators were evident and no indication of apparent practice effect was found. The SYSTEMS was found to have desirable levels of sensitivity (83% and 92%), specificity (76% and 95%), and likelihood ratio for cognitive impairment (3.63 and 17.5) when compared with neurologic judgments and the Differential Ability Scales, respectively. (J Child Neurol 1999; 14:772-780).

This study investigated the relationship between the Bracken Basic Concept Scale and the Differential Ability Scales with 35 at-risk preschoolers between the ages 3–6 and 5–11. A Pearson product-moment correlation coefficient of .70 was obtained between the Bracken Basic Concept Scale Total Test scores and the General Conceptual Ability scores of the Differential Ability Scales. This association supports the use of the Bracken scale to predict intelligence if replicated with a larger sample and specific handicaps. In addition, support for the administration of the more brief Bracken School Readiness Composite compared to using the Bracken Total Test score in the prediction of the Differential Ability Scales General Conceptual Ability score was found.

The adaptive behavior of forty-one 4- through 8-year-olds with Williams syndrome was assessed using the Vineland Adaptive Behavior Scales-Interview Edition. Based on the cognitive and personality profiles characteristic of children with this syndrome, we predicted that the domains of Socialization and Communication would be relative strengths, whereas Daily Living Skills and Motor Skills would be relative weaknesses. We also expected that Socialization Skills would be more advanced than Communication skills, and that within the Socialization domain, interpersonal skills would be stronger than play/leisure or coping skills. All predictions were confirmed. Adaptive behavior standard score was not related to CA. The children earned similar overall standard scores on the Vineland and the Differential Ability Scales. Interrelations among adaptive behavior, cognitive abilities, and personality characteristics are discussed.