Use of the Peabody Picture Vocabulary Test with the educationally handicapped

Despite widespread use of the Peabody Picture Vocabulary Test (PPVT) as a measure of intelligence for educationally handicapped students, few studies have related PPVT scores of such students to their scores on the Wechsler Intelligence Scale for Children (WISC). Using 100 public school students consecutively referred for learning difficulties, their mean PPVT IQ (97.75) was found to be consistently and significantly higher than WISC Full Scale IQ (89.65), Verbal IQ (88.68), and Performance IQ (92.73). Correlations between the PPVT IQ and the WISC Full Scale, Verbal, and Performance IQs were .70, .69, and .54, respectively. A tabular summary of previous studies comparing PPVT and WISC IQs is included.     

Relationship of scores on PPVT-R and WISC-R with special education children and youth

Comparisons of the Peabody Picture Vocabulary Test-Revised and the Wechsler Intelligence Scale for Children-Revised were made with 104 children diagnosed as learning disabled and mentally retarded. Significant but modest correlations were found between all but one of the WISC-R scaled scores (i.e., Coding) and PPVT-R standard scores, and between WISC-R IQs and PPVT-R standard scores. Significant differences were found among mean Verbal, Performance, and Full Scale IQs and mean PPVT-R standard scores. The PPVT-R standard scores underestimated WISC-R Verbal IQs by 7 points, WISC-R Performance IQs by 17 points, and WISC-R Full Scale IQs by 11 points.     

WAIS test-retest reliability for a clinical out-patient sample.

WAIS test-retest reliabilities were calculated for a clinical out-patient sample with testing intervals varying from 1 to 10 yr. There was no relationship between test-retest interval and the stability of test scores and the correlations between IQs were quite satisfactory (Full Scale IQ = .897, Verbal IQ = .906, Performance IQ = .876). Reliabilities remained high even when the sample was divided by diagnosis into organic, neurotic, personality disorder, and schizophrenic subgroups.     

Scoring reliability on the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III)

Nineteen psychologists and 19 graduate students scored two Wechsler Adult Intelligence Scale-Third Edition patient protocols. Mean IQs and indexes were similar across groups, but the ranges for Verbal IQ (VIQ), Performance IQ (PIQ), and Full Scale IQ (FSIQ) on one protocol were 25, 22, and 11 points, respectively. For both protocols taken together, percentages of agreement with the "actual" IQs for psychologists were only 26.3 for VIQ, 36.8 for PIQ, and 42.1 for FSIQ. For students, percentages were 15.8 for VIQ, 23.7 for PIQ, and 31.6 for FSIQ. The percentages of FSIQs that fell within +/- 1 standard error of measurement of the actual IQs were 89.5 for psychologists and 76.3 for students. Scoring error also had a negative impact on index scores. Both groups were confident about their scoring accuracy.     

The relationship between WAIS-R abilities and speed of processing in a word identification task

Matched to the proportions found in the U.K. census data for a range of demographic variables (age, sex, and socioeconomic status) 123 participants were tested on the Wechsler Adult Intelligence Scale-Revised (WAIS-R) and a test of the minimum presentation time required to identify tachistoscopically presented words. The correlations between the sum of the scaled scores for Full, Verbal, and Performance subtests and the log of the identification measures were -0.40, -0.22, and -0.51, respectively. These results are in line with those observed between the WAIS-R measures and standard visual inspection time (IT). Confirmatory factor analysis indicated that a three-factor model of intelligence with Verbal, Performance, and Attention/Concentration factors, and with the identification threshold loaded on the Performance factor alone, represented a better fit to the data than either a single general factor model or a two-factor model with Verbal and Performance factors. These results are in line with findings in the IT literature (Deary, 1993) that speed of information processing is significantly related to performance IQ but not to verbal IQ.     

Concurrent and predictive validity of the Kaufman Assessment Battery for Children with a Navajo sample

The aim of this investigation was to examine the mean scores and predictive validity coefficients obtained from the Wechsler Intelligence Scale for Children-Revised (WISC-R), the Kaufman Assessment Battery for Children (K-ABC), and the Peabody Individual Achievement Test (PIAT). The K-ABC and the WISC-R were administered 1 week apart in counterbalanced order to 35 Navajo children aged 6–12$\text{1}\text{2}$ years (mean 8–9 years), followed 10$\text{1}\text{2}$ months later by administration of the PIAT. The K-ABC yielded an overall mean of 95.0, which is significantly higher than the WISC-R Full Scale IQ mean of 86.9. All WISC-R and K-ABC global scores correlated significantly except the WISC-R Verbal and K-ABC Nonverbal scales. The WISC-R Verbal and Full Scale IQs and all five K-ABC scales correlated significantly with the PIAT Total Test standard scores. However, the K-ABC Achievement scale correlated significantly higher with the PIAT Total Test than with the WISC-R Verbal and Full Scale IQs. The implications of these findings are discussed.     

The Relationship Between the WISC-III and the Kaufman Brief Intelligence Test with Students Referred for Gifted Evaluation

A tolal of 29 students (mean age = 7.96 yrs) who were referred for gifted evaluation in an affluent suburban school district in Western Pennsylvania were administered the Kaufman Brief Intelligence Test (K-BIT) and the WISC-III. Paired t-tests comparing the K-BIT mean IQ (120.59) with the WISC-III Verbal (123.65), Performance (118.86) and Full Scale (122.86) IQs yielded no statistically significant differences (t (28) = 1.49, p = .15; t(28) = -0.74, p = .47; t(28) = 1.35, p = .19, respectively). Correlational analyses indicated that the K-BIT and WISC-III Verbal (r = .35. p < .05), Performance (f = .35, p < .05), and Full Scale IQs (r = 53, p < .01) correlated significantly. The limitations and implications of the study are discussed.     

Correlations for Wechsler Intelligence Scale for Children--Revised and the Wechsler Preschool and Primary Scale of Intelligence for Iranian children.

This study focused on the relationship between the Wechsler Intelligence Scale for Children--Revised (WISC--R) and the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) given to 40 6-yr.-old Iranian children. Pearson correlations between the WISC--R and the WPPSI IQs and between scaled scores on the corresponding subtests were significant. The comparison of mean IQs and scaled scores indicates that the WISC--R yielded a significantly higher Verbal IQ and higher scores on Information, Vocabulary, Comprehension, and Picture Completion than the WPPSI. The mean difference between corresponding Verbal and Full Scale IQs was not significant. These results suggest that scores on the two instruments correlated well for these 6-yr.-old Iranian children and the content on which IQs for the recently restandardized WISC--R and WPPSI are based are related.     

WAIS-R and MMPI profiles of men who have sexually assaulted children: evidence of limited utility

Wechsler Adult Intelligence Scale-Revised (WAIS-R) data were compiled on 101 male sexual offenders of children, and Minnesota Multiphasic Personality Inventory (MMPI) profiles were compiled for a subsample of 81 of these subjects in a replication and extension of the Hall, Maiuro, Vitaliano, and Proctor (1986) MMPI study. The MMPI profiles were heterogeneous and had multiple elevations. No significant relationships between the WAIS-R Full Scale IQ, WAIS-R Performance IQ Minus Verbal IQ Index, or the MMPI scales, and offense characteristics were obtained. These results support the hypothesis of Hall et al. (1986) that psychometric instruments may be of limited utility in characterizing or differentiating among sexual offenders on the basis of criminological variables.     

WAIS--R AND MMPI Profiles of Men Who Have Sexually Assaulted Children: Evidence of Limited Utility

Wechsler Adult Intelligence Scale-Revised (WAIS-R) data were compiled on 101 male sexual offenders of children, and Minnesota Multiphasic Personality inventory (MMPI) profiles were compiled for a subsample of 81 of these subjects in a replication and extension of the Hall, Maiuro, Vitaliano, and Proctor (1986) MMPI study. The MMPI profiles were heterogeneous and had multiple elevations. No significant relationships between the WAIS-R Full Scale IQ, WAIS-R Performance IQ Minus Verbal IQ index, or the MMPI scales, and offense characteristics were obtained. These results support the hypothesis of Hall et al. (1986) that psychometric instruments may be of limited utility in characterizing or differentiating among sexual offenders on the basis of criminological variables.     

Relation of cognitive functioning to daily living skills in a geriatric population

A modified version of the Community Competence Scale was administered along with the Wechsler Adult Intelligence Scale--Revised (WAIS--R) to 40 geriatric patients with suspected dementia. Scores on the Competence Scale, a measure of functional daily living skills, were correlated .72 with Full Scale IQs and .77 with Verbal IQs and moderately correlated (.55) with Performance IQs. A number of significant correlations were found between WAIS--R subtests and subscales of the competence instrument. Means and standard deviations for the 10 Competence subscale and total scores are presented.     

Effects on WAIS-III performance IQ (PIQ) and full scale IQ (FSIQ) when object assembly is substituted for each standard performance scale subtest

According to the WAIS-III Administration and Scoring Manual, Object Assembly (OA) may be substituted for any spoiled Performance subtest. This assertion has not been evaluated in a clinical sample. The present investigation reports differences that resulted in Performance IQ (PIQ) and Full Scale IQ (FSIQ) when OA replaced each of the Performance subtests. Participants were 47 referrals for neuropsychological assessment (age M = 45.98 years, SD = 9.82; education M = 13.82 years, SD = 2.78). Results indicated that OA may replace any Performance subtest without seriously altering the summary scores. Differences between the standard IQs and OA-based composites were < 2 points for PIQ and < 1 point for FSIQ. More than 90% of the OA-based composites fell within the 90% confidence limits of the corresponding IQ.     

Comparison of PPVT-R and WISC-R in a mild/moderate handicapped sample

The Peabody Picture Vocabulary Test-Revised, Form L was compared with the Wechsler Intelligence Scale for Children--Revised with a sample of 32 mild/moderate handicapped students (24 boys, 8 girls). Significant correlations were found between the WISC-R Full Scale IQ (.46) and the WISC-R Verbal IQ (.50) and the PPVT-R, but no significant correlation was found between the WISC-R Performance IQ and the PPVT-R (.34). Mean scores on the PPVT-R and WISC-R were significantly different.     

Sustained attention and visual processing speed in children and adolescents with bipolar disorder and other psychiatric disorders

To investigate the cognitive functioning of children and adolescents with bipolar illness, 112 child and adolescent psychiatric inpatients and day-hospital patients at a state psychiatric hospital were administered the Wechsler Intelligence Scale for Children-III (WISC-III) as part of an admission psychological assessment. There were 22 patients with Bipolar Disorder and 90 with other psychiatric disorders; all were between 8 and 17 years of age. The patients with Bipolar Disorder had a mean age of 14 yr., a mean Verbal IQ of 78, a mean Performance IQ of 76, and a mean Full Scale IQ of 75. When their WISC-III scores were compared with those who had Schizophrenia Spectrum disorders (Schizophrenia and Schizoaffective Disorder), Psychosis Not Otherwise Specified, Attention Deficit Hyperactivity Disorder, and Conduct Disorder and Oppositional Defiant Disorder, there were no significant between-group mean differences for Verbal IQ, but patients with Bipolar Disorder had a significantly lower mean Performance IQ than those with ADHD and those with Conduct Disorder and Oppositional Defiant Disorder. Contrary to the expectation that the patients with Bipolar Disorder might have better sustained attention (higher Digit Span scores) than those with Schizophrenia Spectrum disorders and worse visual processing speed (lower Coding scores) than the other diagnostic groups, the bipolar patients' Digit Span and Coding scores did not differ significantly from those of the other groups. The patients with Psychosis, Not Otherwise Specified had significantly lower mean Performance IQ, Full Scale IQ, and Coding than the ADHD and the Conduct Disorder and Oppositional Disorder groups.     

The WISC-R and the Woodcock-Johnson Tests of Achievement: correlations for exceptional children

The present study concerns correlations of scores on the Woodcock-Johnson Tests of Achievement with those on the Wechsler Intelligence Scale for Children--Revised (WISC--R). Correlations between WISC--R Full Scale, Verbal, and Performance IQ and the Reading Aptitude Cluster, the Mathematics Aptitude Cluster, and the Written Language Aptitude Cluster of the Woodcock-Johnson were expected to be high and support the contention that conventional measures of ability do predict achievement for children. Results confirm the hypothesis. The Verbal IQ was the best one-variable predictor of each aptitude cluster, with R s ranging from .32 to .78.     

The validity of the general ability measure for adults: comparison with WAIS-R IQ scores in a sample of college students with academic difficulties

The present study investigated the validity of the General Ability Measure for Adults (GAMA) by comparing it to the WAIS-R using a sample of 80 college students reporting learning difficulties. Results indicated that the mean GAMA IQ score did not deviate significantly from the mean WAIS-R IQ scores. The GAMA Full Scale IQ correlated significantly with the WAIS-R PIQ, VIQ, and FSIQ scores. However, the obtained correlation coefficient for the GAMA and WAIS-R PIQ significantly differed from the observed correlation coefficient between the GAMA and WAIS-R VIQ, suggesting that the GAMA was more clearly associated with perceptual skills than verbal abilities. When the correlation coefficients between the GAMA and WAIS-R scores were corrected for the effects of range restriction, the correlation coefficients increased, yet demonstrated the same pattern (e.g., GAMA/PIQ,.69; GAMA/VIQ,.36; GAMA/FSIQ,.60). The GAMA s accuracy in predicting individual student performance on the WAIS-R FSIQ also was examined.     

Use of population-specific parameters in generating WAIS-R short forms

One method of increasing the validity of WAIS-R short forms in estimating the standard WAIS-R Full Scale IQ is by using population-specific parameters in generating WAIS-R short forms. Three studies were conducted to evaluate (1) the contribution of age-scaled scores in generating accurate short-form Full Scale IQ, (2) the psychometric properties (validity and reliability) of WAIS-R subtests with a heterogeneous psychiatric population and subsequent development of short forms based on these properties, and (3) the validity of these short forms with respect to Silverstein's (1982) and Cyr and Brooker's (1984) 2- and 4-subtest combinations. Analyses showed (1) the use of age-scaled scores did not increase validity, (2) different subtest combinations were generated based on the population-specific parameters, and (3) increases in validity occurred for some short forms derived from the clinical sample. Despite increases in validity, clinicians and researchers are cautioned about the use of short forms in clinical practice.     

Discrepancies between premorbid and current IQ as a function of progressive mental deterioration

The declining cognitive functioning typically found in patients with Alzheimer's disease presents an opportunity to study that decline. The changing magnitude of ever widening discrepancies between premorbid estimators of IQ and observed IQ increases as severity of the disease increases. Premorbid IQs estimated by these scores (the National Adult Reading Test-Revised, the reading tests of the Revised and Third Editions of the Wide Range Achievement Test, and a demographically based regression index for the Wechsler Adult Intelligence Scale-Revised) had relatively similar discrepancies from obtained WAIS-R Full Scale IQs in samples of normal elderly (n = 30), and elderly patients diagnosed with mild (n = 30) and moderate Alzheimer's disease (n = 30) dementia. The discrepancies became larger, regardless of premorbid estimator, as disease severity progressed from none to mild to moderate across the samples.     

Comparison of the Test of Nonverbal Intelligence and Wechsler Intelligence Scale for children--revised in rural Native American and white children

The Test of Nonverbal Intelligence (TONI) and Wechsler Intelligence Scale for Children--Revised (WISC--R) were administered to 46 Native American and white students who were suspected by their classroom teachers of having learning handicaps. Pearson correlations between these sets of IQs ranged from .42 (TONI and WISC--R Performance) to .89 (WISC--R Verbal and Full Scale).     

Neuropsychometric correlates of the Mini-Mental State Examination: preliminary data

The present study investigated the neuropsychometric correlates of the Mini-Mental State Examination. 12 consecutive neurological referrals were administered the Mini-Mental State Examination, the Wechsler Memory Scale, and the WAIS--R. Pearson product-moment correlations suggest moderate association between scores on the Mini-Mental State Examination and Wechsler Memory Scale but less robust relationships between scores on the Mini-Mental State Examination and WAIS--R Full Scale, Verbal, and Performance IQs.