Comparison of the General Ability Measure for Adults and the Kaufman Adolescent and Adult Intelligence Test with college students

Ninety‐four college students were administered the GAMA and KAIT. GAMA IQs were significantly and moderately correlated with KAIT Fluid, Crystallized and Composite IQs, supporting the convergent validity of this instrument. Although significant correlations between measures emerged and nonsignificant differences were found between mean scores across these instruments, GAMA IQ scores did not accurately predict KAIT Composite IQ scores when GAMA IQ scores were compared to KAIT Composite IQs. Similarly, when the sample was divided into two groups by ability level, GAMA IQs accurately estimated the intelligence for individuals of Average and Below Average intelligence, but underestimated the KAIT Composite IQ scores by 4 points for the Above Average group. Implications of the findings are discussed and suggestions for future research are provided. © 2002, Wiley Periodicals, Inc.     

The exchangeability of brief intelligence tests for children with intellectual giftedness: Illuminating error variance components’ influence on IQs

This study examined the exchangeability of total scores (i.e., intelligent quotients [IQs]) from three brief intelligence tests. Tests were administered to 36 children with intellectual giftedness, scored live by one set of primary examiners and later scored by a secondary examiner. For each student, six IQs were calculated, and all 216 values were submitted to a generalizability theory analysis. Despite strong convergent validity and reliability evidence supporting brief IQs, the resulting dependability coefficient was only .80, which indicates relatively low exchangeability across tests and examiners. Although error variance components representing the effects of the examiner, examiner‐by‐examinee interaction, the examiner‐by‐test interaction, and the test contributed little to IQ variability, the component representing the test‐by‐examinee interaction contributed about one‐third of the variance in IQs. These findings hold implications for selecting and interpreting brief intelligence tests and general testing for intellectual giftedness.     

Differential genetic etiology of reading disability as a function of IQ

To test the hypothesis that the genetic etiology of reading disability differs as a function of IQ, composite reading performance data from 223 pairs of identical twins and 169 pairs of same-gender fraternal twins in which at least one member of each pair was classified with reading disability were subjected to multiple regression analysis (DeFries & Fulker, 1985, 1988). In the total sample, heritability of the group deficit in reading performance (h(g)2) was .58 (+/- .08). However, when the basic regression model was fitted separately to data from twin pairs with average Wechsler (1974, 1981) full scale IQ scores below 100 or 100 and above, resulting estimates of h(g)2 were .43 and .72, respectively, a significant difference (p < or = .03, one-tailed). The results of fitting extended regression models to reading performance and continuous IQ data provide evidence that the genetic etiology of reading disability differs as a linear function of IQ (p < or = .007, one-tailed). These results suggest that IQ is relevant for the diagnosis of reading disability and that environmental influences may be more salient as a cause of reading difficulties in children with lower IQ scores.     

A comparison of the Slosson intelligence test and the WISC-R with elementary school children

The WISC-R and the Slosson Intelligence Test (SIT) were given to 69 randomly selected children in grades one through six in an urban school system. A regression equation for predicting WISC-R full scale IQ from SIT was developed. Previous studies had reported that SIT IQs tended to be consistently higher than WISC-R IQs. The present study revealed that SIT IQs were considerably higher than WISC-R IQs in the upper range and slightly lower in the lower range. A possible reason for the discrepancy is that the present study used a normal population and previous studies used restricted ranges. It was concluded that the SIT provides a good estimate of WISC-R full scale IQs when a regression equation is used. It was recommended, however, that educational placement decisions should not be made on the basis of any single IQ measure.     

Screening for giftedness with the Slosson and the scale for rating behavioral characteristics of superior students

Children who had been nominated as potential candidates for gifted programs were assessed to determine the relationships among certain behavioral and intellectual characteristics. Records were compiled listing 132 first- through eighth-grade children's race, sex, age, grade level, Slosson Intelligence Test (SIT) IQ scores, Scale for Rating Behavioral Characteristics of Superior Students (SRBCSS) scores, and WISC-R IQs. Only children achieving SIT IQs of 130 or higher were included. A regression equation for the prediction of a WISC-R Full Scale IQ score from a given SIT score was computed and compared to that developed for predicting the WISC-R IQ in another study. All variables except SIT IQ were poor predictors of WISC-R IQ scores. A moderate correlation was computed between SIT and WISC-R Verbal and Full Scale IQ scores. A somewhat lower, but still significant, degree of relationship was found between SIT and WISC-R Performance IQ scores. Some difficulties with using the SIT as a screen for gifted programs are discussed.     

Comparison of the slosson intelligence test,revised norms,and WISC-R for children with learning problems and for gifted children

The Slosson Intelligence Test (revised norms) (SIT) and the WISC-R were compared in two samples of children. In the first sample, there were 34 black and 27 white rural Southeastern Alabama children being considered for special education classes. In the second sample, there were 4 black and 81 white suburban Alabama children being considered for classes for the talented and gifted. In both samples, correlations between the SIT IQ and WISC-R Full Scale IQ were significant (rs of .70 and .48, respectively). However, in the special education sample, SIT IQs were significantly higher than WISC-R Full Scale IQs by about 7 points. The results from both samples provide a moderate degree of support for the concurrent validity of the revised SIT norms, using the WISC-R as the criterion. However, the IQs on the two tests may not be interchangeable.     

A comparison of WISC and WISC-R results of urban educable mentally retarded students

Twenty urban EMR students' WISC-R scores were compared with their previously administered WISC scores. The average interval between administrations was approximately three years. Significant coefficients of correlation were obtained between five corresponding subtests and between Performance IQs and Full Scale IQs. Results from t tests for correlated data indicated that mean WISC-R Verbal, Performance, and Full Scale IQ scores were not significantly lower than their corresponding WISC scores. The results of this study indicated that WISC-R scores in comparison to WISC scores appeared to be more stable in the lower IQ ranges and less vulnerable to cultural bias.     

Relationship between PPVT and WISC-R in children with reading disabilities

The Peabody Picture Vocabulary Test (PPVT), Form A was compared to the Wechsler Intelligence Scale for Children-Revised (WISC-R) in two samples of children with reading disabilities. One group of 14 children, referred to a university clinic, were administered the WISC-R, followed by the PPVT. The second group of 38 children from a private learning disability center were administered the PPVT first, followed by the WISC-R. In the combined sample, the PPVT IQ (X̄ = 109.2) was significantly higher than the WISC-R Verbal IQ (X̄ = 98.9), Performance IQ (X̄ = 97.0), and Full Scale IQ (X̄ = 97.5). Similarly, the PPVT IQ was significantly higher than the WISC-R Full Scale in both samples separately, regardless of which test was administered first. In one case, the PPVT IQ was 50 points higher than the WISC-R IQ. Correlations between the PPVT and WISC-R Verbal, Performance, and Full Scale IQs were significant (rs = .56, .29, and .50, respectively). The results suggest that the two tests do not provide interchangeable IQs for a population of reading disabled children.     

The WISC-R as a predictor of achievement

This study investigated the validity of the WISC-R IQs as predictors of achievement as measured by the PIAT. Both tests were administered to 188 children referred to the author because of learning problems. Regression analyses were run with each of the PIAT subtests and the total score as criteria and the WISC-R IQs as predictors. Each of the IQs was a significant predictor of each of the PIAT subtests, but the Verbal IQ predicted best. Regression equations were provided and several indications of the importance of the results were presented.     

A comparison between the WISC and WISC-R among educable mentally retarded students

The study compared differences and similarities between WISC and WISC-R scores for 48 ten- and thirteen-year-old EMR students, who were matched according to sex and race. The WISC-R yielded significantly lower VS, PS, and FS IQ scores than the WISC for this predominantly rural Georgia population. The FS IQ scores from the WISC-R averaged 7.5 points lower than the WISC FS IQs, with similar differences noted for VS and PS scores. There was no significant difference in FS IQs between the two age groups. Results suggest that many children classified as “Borderline” or slightly above by the WISC will be classified as “Mentally Deficient” by the WISC-R.     

A longitudinal study of relations between outer-directedness and IQ changes in preschoolers.

The study was designed to determine whether outer-directedness, measured by glances at E during object assembly tasks administered according to the Turnure and Zigler (1964) procedure, predicts changes in preschoolers' Binet IQs over 6 months. With MA as a covariate to control for the small but significant relationship betweeen glances and developmental level, an ANOCOVA showed a significant interaction resulting from increases in the IQs of non-outer-directed Ss and declines in the IQs of outer-directed Ss. Glances at E's puzzle while S assembled his own were unrelated to glances at E or to IQ changes, but, unlike glances at E, were significantly related to improvements in performance from puzzle 1 to puzzle 2.     

Stability of WISC-R scores in children with learning difficulties

Student records of 130 children with learning difficulties who had been tested twice were examined to determine the stability of WISC-R scores over time. There were significant losses in Verbal IQ and Full Scale IQ. Subjects in the above-average IQ range had greater losses in Verbal IQ and Full Scale IQ and greater gains in Performance IQ than did those in the below-average IQ range. Children initially tested before age 8 had a significant IQ loss, but those tested after age 8 maintained a constant IQ. The WISC-R is most frequently administered to children with learning difficulties. Results presented here suggest that the IQs in this population are not as stable as was previously thought, and this may provide a rationale for the periodic readministration of the WISC-R.     

Discrepancies between IQ and index scores for a clinical sample of students: Useful diagnostic indicators?

Discrepancies between IQ and Index scores on the WISC-111 were investigated for a sample of students with SLD (n = 202), with MR (n = 115), and evaluated but not classified (n=159). Mean Verbal and Performance IQ discrepancies, though significantly different for each sample, were smaller than those reported in the WISC-III manual for the normative sample. Similarly, the Index score comparisons indicated differential functioning for the three samples, with the exception of the Verbal Comprehension and Freedom from Distractibility Index discrepancy. Moreover, the Performance IQ was higher than the Verbal IQ for all three samples. Consistent with the WISC-R literature, discrepancies between Verbal and Performance IQs and higher Performance than Verbal IQs are not diagnostic indicators of abnormalities.     

Validity of the Terman-Merrill abbreviated version of the Stanford-Binet,form L-M

The validities of IQs obtained from independent administration (T-M) vs. the rescoring method (SF) of the short form of the Stanford-Binet, Form L-M were investigated, using the Full Scale Binet IQ (S-B) as criterion. It was hypothesized that the independent or separate administration procedure introduced new variables which when allowed to operate would produce a more realistic picture of the relationship between the short form and S-B IQ. Seventy-six first and second graders were given the T-M and S-B in a counterbalanced order. The results indicated that the T-M, depending on test sequence, correlated significantly different with the S-B IQ than did the SF rescoring method. Caution was advised for users of the T-M as a time-saving estimate of intelligence.     

Correlations between WISC-R subtests and verbal,performance, and full scale IQ scores for minority group children

The relationship between WISC-R subtest scores and Verbal, Performance, and Full Scale IQs was investigated for a sample comprised of rural Appalachian children. The sample was comprised of both white and black children who might be described as culturally different by virtue of low family income and residence in the mountainous areas of Virginia and North Carolina. Data analysis consisted of computing product-moment correlations (rs) between each of the ten subtests and the Verbal, Performance, and Full Scale IQs. Correlations between individual subtests and the FS IQ ranged from.49 through.63, but none of the differences between these rs were large enough to attain significance. Correlations between the verbal subtests and Verbal IQ ranged from.64 for Comprehension up to.78 for Vocabulary. For the performance subtest, the rs ranged from.54 between Coding and the Performance IQ up to.72 for Object Assembly.     

Subtest scatter on the WISC-R with children of superior intelligence

Subtest scatter on the WISC-R was examined by analyzing Verbal-Performance IQ discrepancies, subtest scaled-score ranges and subtest scaled-score standard deviations of 290 psychoeducationally normal 9-year-old children whose IQs ranged from 100 to 140+. Although there were no differences between average and superior IQ groups on the Verbal-Performance discrepancy measure, substantial differences were found on the measures of subtest scatter where higher IQ groups exhibited substantially more scatter. The results suggest the need for caution in attempting to employ WISC-R subtest scatter as an indicator of learning disabilities with gifted students.     

Review of Research on Parent Training for Parents with Intellectual Disability: methodological issues

A computerised search was conducted in May 1995. PsycLit and Eric databases (1974‐1995 and 1965‐1995, respectively) were consulted. A total of 27 references were listed under the topic of Parent Training Program for Parents with Intellectual Disability. However, the results of the review indicated that only one reference was pertinent which was on basic child care skills training for mothers with mean IQ 74 and the mothers who were regarded as having provided neglectful child care. Through personal communication, 10 studies on parent training programs for parents with intellectual disability were obtained and also reviewed. Eight studies applied single‐subject design; two used quantitative methods; one used both single subject design and statistical analysis. Among the 10 studies, one was basic child‐care skills training, two were decision‐making in child rearing; five of them were safety and related topics, and three were concerned with mother‐child interaction. A total of four studies included mothers with normal IQ as a comparison or to serve as a norm. As a whole, research in parent training programs for parents with intellectual disability is still in its infancy. Much more work needs to be done in the area of basic child care skills, comparative studies, identifying situational and subject characteristics for the best outcome of training, and programming to facilitate generalisation.     

Adolescents earlier diagnosed as dyslexic show major IQ declines on the WISC-III

Adolescents (n=43) previously diagnosed as dyslexic/reading disabled had markedly lower IQ scores on the newly standardized Wechsler Intelligence Scale for Children (WISC-III) than on the earlier administered WISC-R. The declines for Verbal, Performance, and Full Scale IQs were 10, 12, and 11 points, respectively, which were twice as great as in a subset of the standardization sample given both versions of the WISC. The adolescents did not show a significant decline in standard scores from the Wide Range Achievement Test (Level I to Level II). However, only two subjects had current reading and spelling standard scores above the 25th percentile. The impact of lower WISC-III IQs on guidelines for classification of students as learning disabled is discussed.     

Comparability of the WISC and the WISC-R in normal children of divergent socioeconomic backgrounds

WISC and WISC-R IQs of two groups of normal ten-year-old children from divergent socioeconomic backgrounds (N = 36) were compared in a counterbalanced research design. Generally, all WISC mean IQs were higher than the WISC-R mean IQs for both groups of children. Significantly higher WISC IQs were obtained on the Verbal and Full Scales of the low socioeconomic group and on the Performance and Full Scales of the high socioeconomic group. Correlations between tests for Verbal, Performance, and Full Scale IQs were.95,.79, and.91 for the low socioeconomic group, and.84,.57, and.87 for the high socioeconomic group. Although practice effects did not appear to significantly affect IQs of the low socioeconomic group, various practice effects were observed in the high socioeconomic group. Negative effects were observed for both WISC and WISC-R on the Verbal Scale, whereas positive effects were observed on both Performance and Full Scales in this group. Analysis of simple effects reveals that WISC and WISC-R IQs did not differ significantly upon first administration, but were significantly different upon second administration. Conclusions were drawn that while WISC-R yields a lower IQ estimate than WISC for children of lower ability, results were not so clear for the children of higher ability, due to practice effects which disproportionately favor increases on WISC IQs upon second administration. The greater practice effects found on the WISC have implications for comparisons of the two tests in counterbalanced research designs. Simple randomized or treatment-by-levels design may be more useful in comparisons of the WISC and the WISC-R because of the bias introduced by counterbalanced designs.     

Measuring stability and change in WISC-R IQS

Webster (1988) assessed WISC-R IQ stability in samples of adolescents identified as EMR and LD. It is argued here that Webster used an inappropriate standard error of measurement in his study. This resulted in magnified estimates of the number of individuals who obtained significantly discrepant IQs from one test admnistration to the next. Webster's analyses therefore exaggerated the degree of test-retest instability inherent in WISC-R IQs.