Gender differences in cognitive abilities of learning-disabled females and males

Gender differences in level and pattern of cognitive abilities were examined in 28 LD college-able females (CA 18–25) as compared to 21 LD college-able males (CA 18–25). Both groups were in the average IQ range as measured by the Wechsler Adult Intelligence Scale, with LD males significantly higher on the Full Scale IQ and three out of the four subtests, Picture Completion, Block Design, and Information. The LD females performed significantly better on the Digit Symbol subtest. The hierarchies of subtest performance and Bannatyne and ACID category scores were compared. LD females have strengths in visual-motor abilities and verbal conceptualization, while the LD males’ highest abilities were nonverbal visual-spatial confirming earlier studies on younger LD individuals and non-LD males and females. Performance on the Digit Symbol subtest was the next to the lowest for the males, the highest for females. However, for both groups, short-term and long-term memory for digits and factual knowledge and mental arithmetic problem solving were relative weaknesses. Results indicate different patterns of cognitive abilities in LD females and males which have implications for identification, service, and prognosis for the learning disabled, especially females.     

Diagnostic utility of the K-ABC and WISC-R/PIAT in determining severe discrepancy

The basic question addressed in this study was whether the discrepancies found between the Mental Processing Composite (ability component) and the Achievement subtests of the Kaufman Assessment Battery for Children (K-ABC) corresponded with the discrepancies found between the WISC-R Full Scale IQ and the PIAT subtests, or whether use of the K-ABC over the WISC-R and PIAT results in the identification of different students. The differences were evaluated using four standard score procedures for calculating a severe discrepancy. It was found that the K-ABC and WISC-R/PIAT approaches to the determination of a score difference resulted in the identification of different populations of students. The high average PIAT standard scores together with the lower subtest reliabilities appeared to be the primary source of disparity between the K-ABC and WISC-R/PIAT comparisons.     

The role of sex differences in the referral process as measured by the Peabody Picture Vocabulary Test-Revised and the Wechsler Intelligence Scale for Children-Revised

The Peabody Picture Vocabulary Test-Revised (PPVT-R) and the Wechsler Intelligence Scale for Children-Revised (WISC-R) are two tests that are often used in the assessment process for special education referrals. Sex differences apparent in these tests were examined in a sample of Arkansas school children who were first-time referrals for a psychological evaluation. The subjects' PPVT-R standard scores, WISC-R IQ scores, and WISC-R subtest scores were divided into groups according to one-year intervals from ages 6 through 16. A separate 2 × 11 (subjects' sex x subjects' age) analysis of variance was performed for each dependent variable. Results indicated significant sex differences among WISC-R Full Scale, Verbal, and Performance IQs and PPVT-R standard scores (p < .01). Several WISC-R subtests also revealed significant sex differences. Further significant sex differences were indicated at several age groups on each dependent variable, with males consistently scoring higher than females on 87%. of the dependent measures excluding the WISC-R subtest Coding, on which females scored higher. Implications concerning the referral process are discussed.     

The relationship between the Wechsler Intelligence Scale for Children-Revised and the Wechsler Intelligence Scale for Children-III scales and subtests with gifted children

Each year thousands of children are evaluated or reevaluated utilizing the current edition of the Wechsler Intelligence Scale to determine their eligibility for gifted programs. The Wechsler Intelligence Scale for Children-III (1991) is new enough that only limited research is available on how it compares to the previously used Wechsler Intelligence Scale for Children-Revised (1974). The purpose of this study was to determine the comparability between the previously dominant intelligence scale, the WISC-R, and the revised WISC-III with gifted children. The results of this study indicate that the latest revision (WISC-III) and the earlier version (WISC-R) produce remarkably similar scale and subtest scores when administered under clinical conditions to gifted children. All 51 children determined eligible through the administration of one of these two Wechsler tests would have been eligible for services had the other test been administered. The Verbal and Performance scale IQ scores were within two points of each other across the two test administrations, while only a one-point difference existed between the Full Scale IQ scores. The Arithmetic, Comprehension, and Object Assembly subtest scores were in high agreement across the two administrations (p<.01). The level of agreement between some subtests across the two administrations suggests that clinical judgment is just as important as scores in considering who is eligible for gifted programs.     

Differences required for significance between Wechsler verbal and performance IQs and WIAT subtests and composites: The predicted-achievement method

This paper provides tables of critical values for determining statistically significant discrepancies between Wechsler Verbal/Performance IQ and WIAT subtest and composite scores based on a predicted-achievement method. It is recommended that these tables be used when a statistically significant and diagnostically meaningful Verbal IQ-Performance IQ discrepancy exists rendering either of these IQs a better estimate of a student's ability than the Full Scale IQ. Issues regarding the use of discrepancy formulas in the assessment and diagnosis of learning disabilities are discussed, and basic considerations for using the critical values tables are provided.     

A comparison of the peabody individual achievement test,the metropolitan achievement test,and the otis-lennon mental ability test

In order to clarify the concurrent validity of the Peabody Individual Achievement Test (PIAT) and the Metropolitan Achievement Test (MAT), product-moment correlations were computed for all subscores and total scores for 26 normal-range public school third-grade girls and boys. The reading comprehension subtests correlated.81, spelling.88, and PIAT Mathematics with MAT Total Math.64. Correlations were computed for the Otis-Lennon Mental Ability Test and the PIAT General Information subtest as.77, and the Otis-Lennon and the PIAT Total Test scores as.79. Concurrent validity of the PIAT with both tests is tentatively considered adequate except in the area of mathematics, in which the PIAT, relative to the MAT, appears to be reflecting ability to handle math concepts (.68) more accurately than math computation (.41) or math problem solving (.56). Correlations with IQ partialed out suggest the PIAT Total Test, and PIAT and MAT reading and spelling measures, are relatively uninfluenced by IQ variations, whereas with IQ held constant, the weak positive correlations between the PIAT and MAT math subtests became essentially random relationships.     

The reliability of the WISC-R performance scale with deaf children

Though the Wechsler tests are widely used to assess the intellectual ability of hearing impaired children, data on the reliability of the WISC-R with this population have been lacking. The Performance Scale of the WISC-R was administered to 59 prelingually deaf children attending a state-supported day school program. The reliability coefficients and standard errors of measurement were computed for each subtest and for the Performance Scale IQ. The results compare favorably with those found by Wechsler with the standardization sample.     

The Wechsler Preschool and Primary Scale of Intelligence: Difficulty order of subtest questions

Theoretically and pragmatically the subtest questions of the Wechsler Pre-school and Primary Scale of Intelligence are assumed to be ordered from least to most difficult. The purpose of this study was to test whether or not the order was appropriate for a sample other than that used for standardization. Data consisted of test records of 89 females and 62 males tested at a private school over four years. Mean Full Scale IQ of the sample was 118. Calculation of proportion of the sample passing each item and Guttman Reproducibility Coefficients for each subtest suggested changes in the order of questions of the Vocabulary, Picture Completion, Similarities, and Comprehension Subtests. However, though questions were misordered for the present sample as a result of presenting them in the order prescribed in the test manual, the misordering was not great enough to seriously affect subtest scores or the interpretation of intratest scatter.     

Cognitive functioning as measured by the WISC-R: do children with learning disabilities have distinctive patterns of performance?

Patterns of performance on the Wechsler Intelligence Scale for Children-Revised (WISC-R) have been proposed as useful tools for the identification of children with learning disabilities (LD). However, most of the studies of WISC-R patterns in children with LD have been plagued by the lack of a typically achieving comparison group, by failure to measure individual patterns, and by the lack of a precise definition of LD. In an attempt to address these flaws and to assess the presence of patterns of performance on the WISC-R, we examined data from 121 children with typical achievement (TA), 143 children with reading disabilities (RD), and 100 children with a specific arithmetic disability (AD), ages 6 to 16 years. The results indicated that the RD and AD groups had significantly lower scores than the TA group on all the Verbal IQ subtests. Many of the children with AD and RD showed a significant difference between Verbal and Performance IQ scores, but so did many of the typically achieving children. Although there were some children with LD who showed the predicted patterns, typically, 65% or more of the children with LD did not. Furthermore, a proportion of the TA group-generally not significantly smaller than that of the RD and AD groups-showed discrepancy patterns as well. Our results indicate that the patterns of performance on intelligence tests are not reliable enough for the diagnosis of LD in individual children. Therefore, it might be more profitable to base the detection of an individual's LD on patterns of achievement test scores.     

Relationship between WISC-R and WRAT in children referred for learning difficulties

Correlations between the WISC-R Full, Verbal, Performance, and Freedom from Distractibility Scale IQs, WISC-R subtest scaled scores, and Wide Range Achievement Test Reading, Spelling, and Arithmetic standard scores were computed for a sample of 114 children (64 boys, 50 girls), aged 6 to 16 years, who were referred for psychological evaluation because of academic or learning difficulties. The Full Scale IQ, Verbal Scale IQ, and Freedom from Distractibility IQ correlated moderately with the three achievement area standard scores (rs of .48 to .59). However, the Performance Scale IQ correlated minimally with reading and spelling scores (rs of .26 and .27), but moderately with arithmetic scores (r = .40). The results support the concurrent validity of the WISC-R.     

Differences between WISC‐R and WISC‐III performance scale among children with ADHD

Reviews involving the Wechsler Scales for children suggest that Full Scale IQ scores on the Wechsler Intelligence Scale for Children, Third Edition, average 5 to 6 points lower than scores on the second edition of the scale [WISC‐R, Wechsler, D. (1974). Zimmerman & Woo‐Sam, 1997], with the differences distributed disproportionately over subtests, i.e., with larger discrepancies found within the Performance Scale (Wechsler, 1991). Changes on the revised subtests of the WISC‐III Performance Scale may place children with ADHD at a disadvantage compared to their performance on analogous WISC‐R subtests. We examined IQ test performance in 122 unmedicated children with ADHD (61 given the WISC‐R, 61 given the WISC‐III), and 46 children from a healthy, comparison group (23 given the WISC‐R, 23 given the WISC‐III). The ADHD and comparison group samples were matched for sex and for Verbal IQ between WISC‐R and WISC‐III. Children with ADHD had significantly lower Performance IQ on WISC‐III compared to the WISC‐R, with the Picture Arrangement subtest showing the most significant difference. In contrast, there were no significant differences between the WISC‐R and WISC‐III cohorts on Performance IQ or any Performance subtests among the comparison group. These findings highlight the importance of examining the comparability of ability test revisions among clinical and non‐clinical populations, and will be especially salient when the WISC‐III is revised. © 2003 Wiley Periodicals, Inc. Psychol Schs 40: 331–340, 2003.     

The impact of the Flynn effect on LD diagnoses in special education

Because of the Flynn effect, IQ scores rise as a test norm ages but drop on the introduction of a newly revised test norm. The purpose of the current study was to determine the impact of the Flynn effect on learning disability (LD) diagnoses, the most prevalent special education diagnosis in the United States. Using a longitudinal sample of 875 school children who were initially diagnosed with LD on the Wechsler Intelligence Scale for Children-Revised (WISC-R), children experienced a significant decline in IQ when retested on the third edition of the WISC (WISC-III) compared to peers who were tested on the WISC-R twice. Furthermore, results from logistic regression analyses revealed that the probability of a rediagnosis of LD on reevaluation significantly decreased, in part, because of this decline on the WISC-III. These results are discussed in terms of their implications for both basic research and educational policy.     

Diagnostic utility of the number of Wisc‐III subtests deviating from mean performance among students with learning disabilities

This paper examined the diagnostic utility of subtest variability, as represented by the number of subtests that deviate from examinees' mean IQ scores, for identifying students with a learning disability (LD). Participants consisted of the 2,200 students in the WISC‐III normative sample and 684 students (Mdngrade = 5; Mage = 10.8) identified as LD. The number of subtests deviating from examinees' Verbal, Performance, and Full Scale IQ by ±3 points for normative and exceptional samples were contrasted via Receiver Operating Curve (ROC) analyses. Results indicated that LD students did not differ from normative sample children at levels above chance. It was concluded that deviation of individual subtest scores from mean IQ scores has no diagnostic utility for hypothesizing about students with learning disabilities. © 2000 John Wiley & Sons, Inc.     

WISC-R patterns for learning disabled children at three SES levels

WISC-R and socioeconomic status (SES) data were collected on 122 learning disabled (LD) children who had been assigned to self-contained LD classrooms. The children were divided into three groups on the basis of family SES: high, middle, and low. Three questions were explored: (a) Is there a relationship between SES and IQ test scores among LD-labeled children? (b) Is the pattern of subtest scores independent of SES level? (c) Is the Verbal-Performance IQ test score discrepancy independent of SES level? Results supported affirmative answers to all three questions. Discussion centered around the implications of these results for future research on the utility of the WISC-R for diagnostic purposes.     

Effects of two instructional sets on the validity of the Kaufman assessment battery for children–nonverbal scale with a group of severely hearing impaired children

The purpose of the study was to investigate the use of the Kaufman Assessment Battery for Children (K-ABC)–Nonverbal Scale with severely hearing impaired children. The K-ABC was administered to 49 children enrolled at a public residential school for the deaf. Test instructions were given to one group employing American sign language (ASL), plus pantomime and gestures, while the other group received pantomime and gesture (PG) instructions only. No significant difference was found between the two group mean nonverbal K-ABC scores. Also, neither group scored significantly different from the K-ABC norms. Both groups scored significantly lower than K-ABC norms on the Spatial Memory subtest. Significant correlations were found between the K-ABC and Wechsler Intelligence Scale for Children-Revised (WISC-R). A significant correlation also was found between K-ABC scores and Reading Comprehension. A post hoc analysis of data found that, regardless of the instructional set, the children scored significantly lower on the Nonverbal K-ABC than they did on the WISC-R Performance Scale. The study provides support for the appropriateness of the K-ABC for use with deaf children.     

Elevated picture completion scores: a possible indicator of hypervigilance in maltreated preschoolers

OBJECTIVE: The Picture Completion subtest of the Wechsler Preschool and Primary Scales of Intelligence-Revised (WPPSI-R) measures visual alertness and the ability to differentiate essential from nonessential details. In children who are hypervigilant as a result of maltreatment, these skills may be over-functioning. It was hypothesized that the Picture Completion subtest scores of these children would be significantly elevated in comparison to their other nonverbal scores and their overall intellectual functioning. METHOD: Fourteen children from a therapeutic day treatment preschool program for maltreated children were administered the WPPSI-R. Standardized discrepancy scores between Picture Completion scores and Performance mean scores (PC-Performance Discrepancy) and the mean of all subscale scores (PC-Overall IQ Discrepancy) were formed and then analyzed. RESULTS: The abused preschoolers scored significantly lower than the population mean on four of the five WPPSI-R Performance subscales. Only on Picture Completion did they score significantly higher. Average PC-Performance Discrepancy and PC-Overall IQ Discrepancy scores were greater than one, indicating that the mean difference of children's Picture Completion score from either their Performance mean score or all of their mean scores was more than one standard deviation. CONCLUSION: Elevated Picture Completion score may serve as a marker for hypervigilance and/or PTSD in children with histories of maltreatment.     

Use of the Kaufman-Assessment Battery for Children with the hearing impaired

The Kaufman-Assessment Battery for Children (K-ABC), a measure of cognitive functioning, was administered to 26 male and 24 female hearing-impaired elementary school students to determine its appropriateness for hearing-impaired children. The Wechsler Intelligence Scale for Children-Revised (WISC-R) also was administered. Scores for the present hearing-impaired sample on the K-ABC were compared with the normative group and were correlated with the WISC-R and standard achievement test scores. Results showed that both the Simultaneous Processing Scale and the Nonverbal Scale seemed appropriate for hearing-impaired children, whose scores were similar to those of the test's normative sample. Scores on the K-ABC also correlated highly with scores from the WISC-R. The Sequential Processing Scale was more problematic and not as useful. The K-ABC was significantly related to school achievement. Difficulties in the administration of the instrument with hearing-impaired children also are discussed.     

High-Active Children and Achievement Tests: A two-year follow-up

A two-year follow-up of 52 elementary school children indicated that in fourth grade, as in second grade, language ability, as measured by the WISC-R Vocabulary subtest, was more strongly related to Achievement Test scores among high-actives than among nonhigh-actives. High-active children of low-to-average language ability had significantly lower achievement test scores than nonhigh-actives, with significant decrement in scores in Reading subtest over the two-year period. On the other hand, high-actives of high language ability had scores only slightly lower than nonhigh-actives, with differences that did not reach significance. Discussion centers on implications for further research and for educational interventions for hyperactive children.     

Determining basals for the peabody individual achievement test

The appropriateness of the starting points for PIAT subtests as suggested by the test authors was investigated. For a sample of 113 subjects with an average WISC-R Full Scale IQ of 98, there was an average difference of nearly 8 points between the suggested starting points for the Mathematics subtest and the actual basals. The difference between suggested starting points and basals for the other subtests ranged from 8 to 12 points. It was suggested that the PIAT user start each subtest approximately 8 items below that suggested by the Manual.     

IQ and neuropsychological predictors of academic achievement

Word reading and math computation scores were predicted from Wechsler Abbreviated Scale of Intelligence Full Scale IQ, 10 neuropsychological tests, and parent attention deficit hyperactivity disorder (ADHD) ratings in 214 general population elementary school children. IQ was the best single predictor of achievement. In addition, Digit Span contributed significantly to reading prediction, and the Developmental Test of Visual-Motor Integration (VMI) and Coding contributed to math prediction. The remaining neuropsychological test scores did not significantly improve achievement prediction. Exploratory factor analysis yielded a general ability factor (comprising the four IQ subtests, Digit Span, VMI, reading, and math), five factors made up solely of subtests from single measures (Wisconsin Card Sorting Test, Stroop Color and Word Test, Gordon Diagnostic System, California Verbal Learning Test, and ADHD ratings), a factor consisting of Grooved Pegboard Test and Coding, and a factor consisting of Symbol Search and Animal Naming Test.