A validity study of the slosson intelligence test for use with educable mentally retarded students

The validity of the Slosson Intelligence Test (SIT) was investigated with two age groups of EMR children. The Stanford-Binet and WISC served as concurrent validating criteria. The SIT correlated significantly with the Binet although the SIT mean IQ was significantly higher. No significant differences were found between standard deviations or mental ages of the two tests. The SIT correlated significantly with WISC verbal and full scale with no significant differences found between standard deviations. The SIT mean IQ was significantly below that of WISC verbal, performance, and full scale. Implications for school psychologists are given.     

Problems with the slosson intelligence test for preschool children

The Slosson Intelligence Test (SIT) was administered to 92 preschool children. Because of the considerably above average performance of the group on the SIT, the Stanford-Binet Intelligence Scale was administered to a sample of the group and the results compared to the results on the SIT. The differences between the two sets of scores was highly significant, and as a result the SIT appears to over estimate the performance of average preschool children.     

Assessment of cognitive deficiency with the McCarthy Scales and Stanford-Binet: a correlational analysis.

The present study tested matched samples of 15 retarded and 15 normal children on the Stanford-Binet Intelligence Scale and the McCarthy Scales of Children's Abilities. Pearson correlations between Stanford-Binet IQs and the six McCarthy Scale Indexes for retarded subjects were lower than coefficients obtained from the normal subjects and from previous research. While the General Cognitive Index may be interchangeable with IQ in the Normal range of intellectual functioning, this relationship was not found for the retarded subjects in the present study. The "venerable" Stanford-Binet retains its position as the most broadly applicable measure of intellectual functioning. Implications of the study as well as an outline for future research were included.     

Stanford-Binet and WAIS IQ differences and their implications for adults with intellectual disability (aka mental retardation)

Stanford-Binet and Wechsler Adult Intelligence Scale (WAIS) IQs were compared for a group of 74 adults with intellectual disability (ID). In every case, WAIS Full Scale IQ was higher than the Stanford-Binet Composite IQ, with a mean difference of 16.7 points. These differences did not appear to be due to the lower minimum possible score for the Stanford-Binet. Additional comparisons with other measures suggested that the WAIS might systematically underestimate severity of intellectual impairment. Implications of these findings are discussed regarding determination of disability status, estimating prevalence of ID, assessing dementia and aging-related cognitive declines, and diagnosis of ID in forensic cases involving a possible death penalty.     

The validity of the Comprehensive Test of Nonverbal Intelligence as a measure of fluid intelligence

The current investigation examined the validity of the Comprehensive Test of Nonverbal Intelligence (CTONI), an intelligence test that is purported to measure fluid intelligence. The CTONI was evaluated in comparison with the Kaufman Adolescent and Adult Intelligence Test (KAIT), an established measure of fluid and crystallized intelligence. Ninety-seven adults were administered these instruments in counterbalanced order. Results indicated that the sample's mean CTONI Nonverbal IQ (NIQ) deviated significantly from the mean KAIT Crystallized, Fluid, and Composite IQs. The CTONI mean NIQ underestimated KAIT Fluid and Composite IQs when individual participants were subdivided into existing KAIT ability categories and mean score comparisons were made. Results also indicated that the CTONI NIQ correlated strongly and positively with the KAIT Composite and Fluid IQs. Furthermore, the CTONI Geometric NIQ scale clearly demonstrated discriminant and convergent validity, whereas, the CTONI Pictorial NIQ (PNIQ) did not.     

Comparison of the Token Test of Language Development and the Wechsler Intelligence Scale for Children--Revised

Correlations were calculated between the Token Test of Language Development (Token) and scores of the Wechsler Intelligence Scale for Children--Revised (WISC-R) based on responses from 38 Caucasian children (23 boys and 15 girls) of a semi-rural Northeastern Ohio school district. The relatively low Pearson correlations (.25 to .47) between the standard scores in the Token test and WISC-R IQs are discussed in relation to ability and achievement.     

The effects of skewness on the interpretation of ITPA scaled scores

Studied the degree to which skewed score distributions can affect the interpretation of Illinois Test of Psycholinguistic Abilities (ITPA) (Kirk, McCarthy, & Kirk, 1968) subtest scores. Indices of skewness were determined for the 10 main ITPA subtests for each of the eight age groups which comprised the normative sample (Paraskevopoulos & Kirk, 1969). The ITPA normative sample was drawn from children, both male and female, having abbreviated Stanford-Binet IQs between 84 and 116 and ranging in age from 2 years 7 months to 10 years 1 month. The results indicate that the following subtests were most seriously affected by scale limitations: auditory reception, auditory association, visual reception, manual expression, and grammatic closure. The results suggest that indices of score variability such as average deviation and standard scores must be interpreted with extreme caution when skewness is a significant factor.     

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.     

Can intelligence be estimated from drawings of a man?

There has been some disagreement as to whether intelligence can be estimated reliably and validly from the Goodenough-Harris Draw-A-Man Test (DAM). In order to assess the DAM, 21 graduate students in psychology administered the Harris DAM and either the WISC or Stanford-Binet (S-B) to 158 “normal” children. Discrepancy scores between the DAM and the S-B or WISC indicated that the DAM IQ tends to be below, at times considerably, IQs obtained from individual scales. Moreover, the DAM seemed to be virtually useless in making discriminations among children of average and superior intelligence. The Harris scoring system was not found to be more discriminating than the original Goodenough, and the results provided little encouragement for the practice of estimating intelligence from a child's DAM.     

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).     

Stability of scores for the Slosson Full-Range Intelligence Test

The test-retest stability of the Slosson Full-Range Intelligence Test by Algozzine, Eaves, Mann, and Vance was investigated with test scores from a sample of 103 students. With a mean interval of 13.7 mo. and different examiners for each of the two test administrations, the test-retest reliability coefficients for the Full-Range IQ, Verbal Reasoning, Abstract Reasoning, Quantitative Reasoning, and Memory were .93, .85, .80, .80, and .83, respectively. Mean differences from the test-retest scores were not statistically significantly different for any of the scales. Results suggest that Slosson scores are stable over time even when different examiners administer the test.     

A construct validation study of the Human Figure Drawing Test

To assess whether the Human Figure Drawing Test provides an assessment of nonverbal cognitive maturity, correlations for 31 youngsters who ranged in age from 6-0 to 10-10 on the Human Figure Drawing Test and the Verbal, Performance, and Full Scale IQs of the Wechsler Intelligence Scale for Children--Revised (WISC--R) were examined. Significant correlations were observed for each of the scales, but the value of .69 for drawings and WISC--R Performance IQs was significant, suggesting the assessment that these tests are largely nonverbal. Implications for the role of language were posited.     

IQ stability: the relation between child and young adult intelligence test scores in low-birthweight samples

The stability of IQ from childhood to adulthood in low-birthweight subjects was measured in two independent samples with follow-up intervals of approximately 14 and 9.5 years. In both samples, intelligence was assessed with the WISC at a mean age of 9.5. Twenty-six subjects were retested with the WAIS at a mean age of 23.5, and 78 subjects with the BPP (the Danish Military Draft Board Intelligence Test) at the age of 19.1. Both samples obtained childhood and adult test scores below the expected means. For the Wechsler Verbal, Performance and Full-Scale IQs, the stability quotients were 0.86, 0.86, and 0.89 in the WAIS sample, and the retest correlations for the three IQs with the BPP score were 0.66, 0.65, and 0.74. Thus, the majority of children showed stable patterns of intellectual development from middle childhood to young adulthood.     

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.     

Concurrent validity of the WISC-R factor scores

This study investigated the efficacy of predicting academic achievement as measured by the Wide Range Achievement Test using the factor scores of the Wechsler Intelligence Scale for Children-Revised as potential predictors. Both instruments were administered to 200 school children referred for psychological evaluations. Factor scores for the WISC-R were computed according to equations provided by Gutkin (1978). These factor scores then were regressed in a stepwise manner on the Reading, Spelling, and Arithmetic standard scores from the Wide Range Achievement Test. Stepwise regressions also were performed using the traditional Verbal and Performance IQs as the potential predictors. A comparison was made between the results obtained by use of the factors or the more common scores. The results indicated that the Freedom From Distractibility factor score significantly aided in the prediction of Reading and Spelling achievement and was of primary importance in predicting Arithmetic achievement. When the stepwise results using the different scores were contrasted, the factor scores accounted for appreaciably more variance in Arithmetic than did the traditional Verbal and Performance IQs. Derived regression equations are reported along with a discussion of the interpretability of the Freedom From Distractibility factor.     

Comparing the Stanford-Binet,fourth edition to the WISC-R: A concurrent validity study

This study focused on the concurrent validity of the Stanford-Binet Intelligence Scale, 4th ed. (SB IV) and the Wechsler Intelligence Scale for Children-Revised (WISC-R) in a homogeneous, nonexceptional sample of 32 early elementary school children. Despite the limited nature of the sample, the findings suggested that the SB IV has a significant positive relationship with the WISC-R. The tests displayed a moderate level of common variance. Intercorrelations partially supported the SB IV authors' predictions of relationship between the two instruments.     

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.     

Pilot study of telephone tutoring in reading skills

This study tested the feasibility of tutoring children in reading via telephone sessions. 19 children received tutoring from any of 6 tutors for an average of 7.6 hr. per month. Initially, these children were an average of 10.4 yr. old, in average Grade 4.8, and averaged 2.9 grade levels behind their grade expectations on the Slosson Oral Reading Test. Before tutoring the children had progressed on the Slosson at an average of 0.44 grade levels per year (95% CI = 0.30 to 0.57). The children participated in telephone tutoring for an average of 1.5 yr. During tutoring the students progressed at an average of 2.0 grade levels per year (95% CI = 1.2 to 2.8). The rate of progress during tutoring was significantly greater than that before tutoring (p<.001). The relations between tutors and students appeared to be positive and pleasant. Telephone tutoring seems to be a practical and feasible service delivery method which should be tested further.     

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.     

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.