Journal of Education and Human Development ISSN Volume 5, Issue 1, 2012

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1 Journal of Education and Human Development ISSN Volume 5, Issue 1, 2012 Relationship between the Wechsler Adult Intelligence Scale Fourth Edition () and Woodcock-Johnson-III Normative Update (NU): Tests of Cognitive Abilities (WJ-III COG) Gail M. Cheramie, Associate Professor, University of Houston-Clear Lake, Mary E. Stafford, Associate Professor, University of Houston-Clear Lake, Candice Boysen, Graduate Student, University of Houston-Clear Lake, Jana Moore, Graduate Student, University of Houston-Clear Lake, Callie Prade, Graduate Student, University of Houston-Clear Lake, Abstract This pilot study investigated the relationship of the Wechsler Adult Intelligence Scale () and the Woodcock- Johnson-III: Tests of Cognitive Abilities (WJ-III COG) as related to the Cattell-Horn-Carroll (CHC) theory. Correlations between the instruments using a general adult sample of 30 individuals yielded findings that are consistent with data on CHC relationships and show that certain subtests are true measures of narrow abilities they are designed to measure (e.g., WJ-III COG Picture Recognition measures visual memory) whereas others are multidimensional (e.g., Arithmetic and Matrix Reasoning). This study contributes to the increasing knowledge of CHC broad and narrow abilities. Introduction The measurement of adult intelligence is a major activity undertaken by psychologists, and the Wechsler Adult Intelligence Scale-Fourth Edition (; Wechsler, 2008) is perhaps the most widely used measure for this assessment. The is used not only for assessing the overall general intelligence of examinees 16 through 90 years of age, but also measures various aspects of cognitive functions, such as verbal skills, visual-spatial skills, and memory. The consists of ten core subtests that provide a measure of general intellectual functioning termed the Full Scale Intelligence Quotient and four Index scores Verbal Comprehension Index (consisting of the Similarities, Vocabulary, and Information subtests), Perceptual Reasoning Index (consisting of the Block Design, Matrix Reasoning, and Visual Puzzles subtests), Working Memory Index (consisting of the Digit Span and Arithmetic subtests), and Processing Speed Index (consisting of the Symbol Search and Coding subtests). The Woodcock-Johnson-III: Tests of Cognitive Abilities (WJ-III COG; Woodcock, McGrew, & Mather, 2001; Woodcock, McGrew, Schrank, & Mather, 2007) measures general intelligence and yields an overall score termed General Intellectual Ability; it also measures various aspects of cognitive processing (e.g., verbal skills, visual-spatial skills, memory, auditory processing). The WJ-III COG consists of a set of 20 tests: ten in the Standard Battery and ten more in an Extended Battery. Some of the WJ-III COG tests can be administered to children as young as two years of age, and all of the tests can be administered to individuals from five to 95 years of age. Each WJ-III COG test measures a narrow cognitive ability. The 20 tests can be grouped into various cognitive categories, Cattell-Horn- Carroll (CHC) factors, and clinical clusters. There are fourteen tests that cluster to form the seven broad CHC factors of cognition: Comprehension-Knowledge (consisting of the Verbal Comprehension and General Information tests); Long-Term Retrieval (consisting of the Visual-Auditory Learning and Retrieval Fluency tests), Visual-Spatial Thinking (consisting of the Spatial Relations and Picture Recognition tests), Auditory Processing (consisting of the Sound Blending and Auditory Attention tests), Fluid Reasoning (consisting of the Concept Formation and Analysis-Synthesis tests), Processing Speed (consisting of the Visual Matching and Decision Speed tests), and Short-Term Memory (consisting of the Memory for Words and Numbers Reversed tests). The WJ-III COG refers to its measures as tests, and the uses the term subtests. To be consistent, the term subtests is used for both instruments. Of particular interest to this study are the ten subtests that form the following five factors: Comprehension-Knowledge, Visual-Spatial Thinking, Fluid Reasoning, Processing Speed, and Short- Term Memory. Given the factor structures of both the and WJ-III COG, it is clear that the current conceptualization of intelligence has far surpassed the crudeness of a single overall score and offers more useful measurement of the various aspects of cognitive functions. The best known contemporary conceptualization for the structure of human cognitive abilities is the CHC model (McGrew & Flanagan, 1998). The CHC model is based on an integration of two theories: (a) Cattell-Horn s Gf-Gc theory, which was first proposed over 60 years ago and has been further developed to include several broad factors in addition to fluid (Gf) and crystallized (Gc) intelligence (Horn, 1987); and (b) Carroll s (1993) three-stratum theory based on factor analyses of more than 400 data sets. The term CHC was coined 1

2 by McGrew and Flanagan (1998), and this model serves to provide a paradigm by which intelligence tests are interpreted. Based on this model, intelligence is made up of narrow or Stratum I abilities and broad or Stratum II abilities. A narrow ability reflects greater specialization of a particular ability or skill that exists within a broader ability. Narrow abilities are associated with subtests, while broad abilities are associated with clusters or factors of such subtests. For example, Short-Term Memory is a broad ability made up of narrow abilities such as memory span and working memory. The CHC model serves as the basis for the WJ-III COG. Wechsler subtests and indices have been identified as measuring specific narrow and broad abilities under the CHC model. Although the relationship between the and the WJ-III COG has not been directly studied, it has been suggested that the follows CHC-inspired structures, and that the broad abilities measured are compatible with the CHC model, including crystallized intelligence, fluid intelligence, visual processing, short-term memory, and processing speed (McGrew, 2009). In 2009, Flanagan, Ortiz and Alfonso created a chart identifying each subtest and its association with the CHC broad and narrow abilities. If these associations are accurate and the WAIS- IV broad abilities are compatible with the CHC model, then scores of the and WJ-III COG should show a strong relationship, and they should particularly show high correlations in the identified narrow abilities. Table 1 presents the subtests that are associated with each broad CHC factor and their respective narrow abilities. Table 1. Relationship of the Core subtests and WJ-III COG tests to CHC Broad Factors and Narrow Abilities Broad CHC Factors Crystallized Intelligence (Gc) Subtests Similarities* & Vocabulary WJ-III COG Subtests Verbal Comprehension Narrow Ability Lexical Knowledge & Language Development Information General Information General Information Visual Processing (Gv) Block Design & Visual Puzzles Spatial Relations Picture Recognition Spatial Relations & Visualization Visual Memory Fluid Intelligence (Gf) Concept Formation Analysis-Synthesis Induction General Sequential Reasoning Matrix Reasoning Induction & General Sequential Reasoning Short-Term Memory (Gsm) Arithmetic** Digit Span Numbers Reversed Working Memory Memory Span & Working Memory Memory for Words Memory Span Processing Speed (Gs) Coding Symbol Search Visual Matching Rate-of-Test Taking Perceptual Speed & Rate-of-Test Taking Decision Speed Speed of Reasoning Auditory Processing *** Sound Blending Auditory Attention Phonetic Coding: Synthesis Speech/General Sound Discrimination & Resistance to Auditory Stimulus Distortion Long-Term Retrieval *** Visual-Auditory Learning Associative Memory Retrieval Fluency Ideational Fluency *According to Flanagan, et al. (2009), the Similarities subtest also measures Induction, a narrow ability under Gf. **According to Flanagan, et al. (2009), the Arithmetic subtest also measures Quantitative Reasoning, a narrow ability under Gf. ***The does not measure these factors; thus, they are not a focus of this investigation and are not included in the statistical analyses. 2

3 Because not all CHC factors are measured on the, adjusted factors have to be calculated in order to directly compare the and WJ-III COG. These adjusted composites were done through the use of a statistical program called the Compositator, and this is discussed in the Procedures section. The purpose of this pilot study is to investigate the relationship between the and the WJ-III COG, specifically as related to correlations between those tests/subtests and index/cluster scores that reflect the CHC model. The following questions were generated to investigate these relationships: I. General Intelligence Investigation a. To what extent is the Full Scale IQ on the related to the General Intellectual Ability of the WJ-III COG? b. To what extent is the Full Scale IQ on the related to the Adjusted General Intellectual Ability (i.e., using unweighted transformations from Compositator and eliminating Ga and Glr) of the WJ-III COG? It is hypothesized that the WJ-III COG Adjusted General Intellectual Ability will have a stronger relationship with the Full Scale IQ due to removal of Long-Term Retrieval (Glr) and Auditory Processing (Ga) tests. II. Cluster Investigations To what extent are the broad indices of the related to the broad CHC factors of the WJ-III COG in the following areas? a. Verbal Comprehension Index and WJ-III COG Crystallized Intelligence b. Perceptual Reasoning Index and WJ-III COG Visual Processing c. Perceptual Reasoning Index and WJ-III COG Fluid Intelligence d. Working Memory Index and WJ-III COG Short-Term Memory e. Processing Speed Index and WJ-III COG Processing Speed III. Subtest Investigations For shared factors/clusters, to what extent are the subtest scores of the related to the subtest scores of the WJ-III COG? Method Participants The and WJ-III COG were administered by graduate students in an intellectual assessment course and a database was created from the protocols. As part of the course requirement, no assessed adult could have a clinical diagnosis. A total of 30 matched and WJ-III COG protocols comprised the sample for this investigation. The tested adults ranged in age from 20 to 62; the mean age of the sample was 35. There were 15 females and 15 males. Instrument The and WJ-III COG were the instruments used in this investigation. All ten core subtests of the had to have been administered (no substitutions) for the protocols to be used in the study. These subtests were used to calculate the Verbal Comprehension Index, Perceptual Reasoning Index, Working Memory Index, Processing Speed Index, and Full Scale IQ. All fourteen tests of the WJ-III COG that comprise the CHC clusters had to have been administered as well. They were used to calculate Crystallized Intelligence, Visual Processing, Fluid Intelligence, Short-Term Memory, Processing Speed, Long-Term Retrieval, Auditory Processing, and General Intellectual Ability. Procedures Protocols were selected from archival data, thus minimizing any bias in protocol scoring and selection. As part of the intellectual assessment course, graduate students assessed adults using the during the first part of the course (within the first 6 weeks) and using the WJ-III COG toward the end of the course (within the last 3 weeks). Each student had to administer the WJ-III COG to an adult to whom they had administered the. The WJ-III COG tests were administered at least 6 weeks after the. Each protocol was checked for clerical and mathematical errors and graded by the course professor. In addition, each graduate student was directly observed in the standardized administration of the. Only the protocols of those students who administered and scored both tests with criterion levels of accuracy of 90% or above were selected for the study. All protocols were scored according to regular procedures. Because the does not measure Long-Term Retrieval and Auditory Processing, but these tests are used in the WJ-III COG to calculate the General Intellectual Ability, an Adjusted General Intellectual Ability needed to be calculated. This was done through the use of the Compositator (Schneider, 2010b), which is a supplement to the WJ-III NU Compuscore and Profiles Program version 3.1 (Schneider, 2010a; Woodcock et al., 2007). The Compositator is able to create custom composite scores from any set of WJ-III COG tests that have been administered as part of that battery. As stated by the author, By default, all new composites are unweighted with each subtest contributing equally to the score of the new composite. This is the method used to create composite scores in most cognitive test batteries other than the WJ-III COG (p. 23). Thus, 3

4 to directly compare the total score from both batteries, the unweighted Adjusted General Intellectual Ability was calculated. The custom composite for the Adjusted General Intellectual Ability consisted of ten subtests and eliminated the two Auditory Processing tests of Sound Blending and Auditory Attention and the two Long-Term Retrieval tests of Visual-Auditory Learning and Retrieval Fluency. The subtests of the have a mean of 10 and standard deviation of 3, while the subtests of the WJ-III COG have a mean of 100 and standard deviation of 15. In order to make direct comparisons between the scaled scores and WJ-III COG standard scores, each subtest was converted to a mean of 100 and standard deviation of 15. For example, a scaled score of 10 on the is equal to a standard score of 100, while a scaled score of 7 is equal to a standard score of 85. Results General Intelligence Investigation The first investigation focused on the extent to which the Full Scale IQ score on the related to the General Intellectual Ability (GIA) score of the WJ-III COG as well as to the Adjusted General Intellectual Ability (A-GIA) score. The results of this investigation can be found in Table 2. Table 2. Correlations between General Intelligence Scores on and WJ-III COG IQ and GIA Scales Full Scale IQ with WJ-III COG General Intellectual Ability Full Scale IQ with WJ-III COG Adjusted General Intellectual Ability ***p<.001 Means (SD) WJ-III COG Means (SD) Correlation (Variance Accounted for) (11.58) (10.54) r =.71*** (49%) (11.58) (10.42) r =.66*** (45%) Both correlations are statistically significant and account for a large proportion of the variance. It was hypothesized that the WJ-III COG Adjusted General Intellectual Ability (A-GIA) would have a stronger relationship with the Full Scale IQ than the WJ-III COG General Intellectual Ability (GIA). As can be seen in Table 2, this hypothesis is not supported. The stronger relationship is between the general intelligence measures of the Full Scale IQ and the WJ-III COG General Intellectual Ability, which accounts for 49% of the variance between these constructs. Cluster Investigations The second investigation focused on the extent to which the cluster scores of the and the WJ-III COG are related. The results of this investigation can be found in Table 3. Table 3. Correlations between Cluster Scores on and WJ-III COG Clusters/Factors Means (SD) WJ-III COG Means (SD) Correlation (Variance Accounted for) Verbal Comprehension Index (14.66) (9.61) r =.82*** (66%) and WJ-III COG Crystallized Intelligence Perceptual Reasoning Index (13.47) (11.41) r =.65*** (42%) and WJ-III COG Fluid Intelligence Block Design + Visual Puzzles (11.74) (9.34) r =.53** (28%) and WJ-III COG Visual Processing a Perceptual Reasoning Index (13.47) (9.34) r =.51** (26%) and WJ-III COG Visual Processing Processing Speed Index and (12.64) (13.63) r =.45* (20%) WJ-III COG Processing Speed Working Memory Index and WJ-III COG Short-Term Memory (10.85) (13.05) r =.42* (17%) a The scaled scores of Block Design and Visual Puzzles were converted to standard scores, added together, and a mean composite score was created; this score was then correlated to the Visual Processing cluster score of the WJ- III COG. * p<.05; ** p<.01; ***p<.001 4

5 All correlations between cluster scores were significantly related. The strongest relationship among cluster scores is that of the Verbal Comprehension Index and WJ-III COG Crystallized Intelligence cluster (r =.82), which accounts for 66% of the variance. The second strongest relationship is that of the Perceptual Reasoning Index and the WJ-III COG Fluid Intelligence cluster (r =.65), which accounts for 42% of the variance. These clusters represent Crystallized Intelligence (Gc) and Fluid Intelligence (Gf), which are the broadest of the clusters. The next strongest relationships involve the Visual Processing (Gv) clusters (r =.53 and.51; 28% and 26% variance, respectively). While statistically significant, the relationships among the Short-Term Memory and Processing Speed clusters account for 17% and 20% of the variance, respectively. Subtest Investigations The third investigation focused on the extent to which the subtest scores of the are related to the subtest scores of the WJ-III COG for those subtests that measure the same broad and narrow areas. Correlations between the relevant and WJ-III COG subtests in this study can be found in Table 4 below. Table 4. Correlations between Subtest Scores on and WJ-III COG WJ-III COG Subtests Subtests Voc Sim Info BD VP MR Arith DS Cod SS VC.68***.55**.73***.35.42*.43*.67***.41* GI.71***.61***.74***.43*.42*.39*.63*** SR ***.44*.54**.39* PR CF.55**.39*.56**.45*.29.37*.57*** A-S.42*.56***.50**.69***.61***.46*.57*** NR.37*.31.47** *.43* MW * * VM *.46* DS * p<.05; ** p<.01; ***p<.001 Subtests: Voc= Vocabulary; Sim= Similarities; Info= Information; BD= Block Design; VP= Visual Puzzles; MR= Matrix Reasoning; Arith= Arithmetic; DS= Digit Span; Cod= Coding; SS= Symbol Search. WJ-III COG Subtests: VC= Verbal Comprehension; GI= General Information; SR= Spatial Relations; PR= Picture Recognition; CF= Concept Formation; A-S= Analysis-Synthesis; NR= Numbers Reversed; MW= Memory for Words; VM= Visual Matching; DS= Decision Speed The contributions of subtests making up each cluster is of specific interest. Table 5 is comprised of the correlations of subtests contributing to the Crystallized Intelligence cluster of the WJ-III COG and the Verbal Comprehension Index of the. The correlation of the two clusters was r =.82, which is significant at the p <.001 level and explains 66% of variance between these clusters. As can be seen, all correlations between the contributing subtests and their counterparts are statistically significant and explain between 30% and 55% of variance. Table 5. Subtest Means, Standard Deviations, and Correlations for the WJ-III COG Crystallized Intelligence cluster and the Verbal Comprehension Index WJ-III COG Voc Sim Info M SD VC.68***.55**.73*** GI.71***.61***.74*** M SD ** p<.01; ***p<.001 Subtests: Voc= Vocabulary, Sim= Similarities, Info= Information WJ-III COG Subtests: VC= Verbal Comprehension, GI= General Information There are two WJ-III COG clusters that are related to the Perceptual Reasoning Index: Visual Processing and Fluid Intelligence. Tables 6 (Visual Processing) and 7 (Fluid Intelligence) summarize these subtest relationships. Table 6 is comprised of the correlations of subtests contributing to the Visual Processing cluster of the WJ-III COG and the Perceptual Reasoning Index of the. The correlation of the two clusters was r =.51, which is significant at the p<.01 level and explains 26% of variance. As can be seen, correlations between the WJ-III COG Spatial Relations subtest and all Perceptual Reasoning subtests (Block Design, Visual Puzzles and Matrix Reasoning) are significant, with the relationship between Spatial Relations and Block Design (.81) being the strongest 5

6 (p <.001). The relationship between Spatial Relations and Visual Puzzles (.44) is significant at the p <.05 level. These are expected relationships as Spatial Relations, Block Design and Visual Puzzles measure the same narrow abilities. None of the relationships between the Picture Recognition subtest of the WJ-III COG and the Perceptual Reasoning subtests are significant. The one unexpected finding is the significant relationship between Matrix Reasoning and Spatial Relations (.54) since Matrix Reasoning is noted to measure a different narrow ability. Table 6. Subtest Means, Standard Deviations, and Correlations for the WJ-III COG Visual Processing cluster and the Perceptual Reasoning Index WJ-III COG BD VP MR M SD SR.81***.44*.54** PR M SD * p<.05; ** p<.01; ***p<.001 Subtests: BD= Block Design, VP= Visual Puzzles, MR=Matrix Reasoning WJ-III COG Subtests: SR= Spatial Relations, PR= Picture Recognition Table 7 is comprised of the correlations of subtests contributing to the Fluid Intelligence cluster of the WJ-III COG and the Perceptual Reasoning Index of the. The correlation of the two clusters was r =.65, which is significant at the p<.001 level. As can be seen, all Perceptual Reasoning subtests correlate significantly to the WJ-III COG Analysis-Synthesis subtest, with unexpected correlations between Block Design and Visual Puzzles; these latter subtests are noted to measure different narrow abilities and a different process (Visual Processing versus Fluid Reasoning). The correlation between Matrix Reasoning and both WJ-III COG subtests is consistent with expectations, since these tests measure the same narrow abilities. Block Design also correlates significantly with Concept Formation; again this is not expected since Block Design is associated with the narrow abilities of Spatial Relations and Visualization, whereas Concept Formation is associated with the narrow ability of Induction. Table 7. Subtest Means, Standard Deviations, and Correlations for the WJ-III COG Fluid Intelligence cluster and the Perceptual Reasoning Index WJ-III COG BD VP MR M SD CF.45*.29.37* A-S.69***.61***.46* M SD * p<.05; ***p<.001 Subtests: BD=Block Design, VP=Visual Puzzles, MR= Matrix Reasoning WJ-III COG Subtests: CF= Concept Formation, A-S= Analysis-Synthesis Table 8 is comprised of the correlations of subtests contributing to the Short-Term Memory cluster of the WJ-III COG and the Working Memory Index of the. The correlation of the two clusters was r =.42, which is significant at the p<.05 level (17% variance explained). As can be seen, three of the four correlations are significant at the p <.05 level. Memory for Words measures the narrow ability of Memory Span and the absence of a significant relationship with Arithmetic is consistent with expectations. Digit Span measures both Working Memory and Memory Span, thus its correlation to both Numbers Reversed and Memory for Words is consistent with the CHC model. Arithmetic, as a measure of Working Memory, should be and is correlated with Numbers Reversed, also a measure of Working Memory. Table 8. Subtest Means, Standard Deviations, and Correlations for the WJ-III COG Short-Term Memory cluster and the Working Memory Index WJ-III COG Arith DS M SD NR.43*.43* MW.02.40* M SD * p<.05 Subtests: Arith= Arithmetic, DS= Digit Span WJ-III COG Subtests: NR= Numbers Reversed, MW= Memory for Words 6

7 Table 9 is comprised of the correlations of subtests contributing to the Processing Speed cluster of the WJ-III COG and the Processing Speed Index of the. The correlation of the two clusters was r =.45, which is significant at the p<.05 level (20% variance explained). Correlations between the Visual Matching subtest of the WJ-III COG and the Coding and Symbol Search subtests are significant (p <.05), and this is consistent with the CHC model in that these subtests measures the narrow ability of Perceptual Speed. Decision Speed measures a different narrow ability (Speed of Reasoning) and the absence of a significant correlation is expected. Table 9. Subtest Means, Standard Deviations, and Correlations for the WJ-III COG Processing Speed cluster and the Processing Speed Index WJ-III COG Cod SS M SD VM.36*.46* DS M SD * p<.05 Subtests: Cod= Coding, SS= Symbol Search WJ-III COG Subtests: VM= Visual Matching, DS= Decision Speed Discussion The Full Scale IQ of the is significantly correlated to both the General Intellectual Ability and Adjusted General Intellectual Ability scores of the WJ-III COG. The mean scores for the Full Scale IQ (108.47), the General Intellectual Ability (108.07), and the Adjusted General Intellectual Ability (111.10) were similar, with no statistically significant differences between these scores. As indicated by the results, the WJ-III COG Adjusted General Intellectual Ability did not have a stronger relationship with the Full Scale IQ as had been hypothesized. In this study, removal of the Long-Term Retrieval and Auditory Processing clusters was only done to establish equivalence between the and WJ-III COG, since the does not measure these processes. However, removal of Long-Term Retrieval and Auditory Processing did not have a substantial impact on the comparative relationship of general intelligence as measured by both instruments. All of the broad indices of the had statistically significant correlations with the broad CHC factors of the WJ- III COG. Of the clusters, the correlation between the measures of Crystallized Intelligence (i.e., Verbal Comprehension Index on and Comprehension-Knowledge cluster of WJ-III COG) was strongest and all subtests within these clusters were significantly correlated. This was expected/ consistent with the CHC model since these clusters and subtests measure the same narrow abilities (i.e., Lexical Knowledge, Language Development, and General Information). The relationship between Visual Processing and the Perceptual Reasoning Index is significant, but this is due to the significant correlations of Block Design, Visual Puzzles, and Matrix Reasoning with the Spatial Relations subtest. The absence of significant correlations with Picture Recognition is expected because this particular WJ-III COG test measures a different narrow ability known as Visual Memory. The absence of significant correlations supports this distinction. The strongest correlation is between Block Design and Spatial Relations and this is due to the fact that they measure the same narrow ability (Spatial Relations). Visual Puzzles and Matrix Reasoning also involve spatial perception, thus it is not unexpected that these subtests would be significantly correlated. What is unexpected is that Visual Puzzles has a lower correlation with Spatial Relations than both Block Design and Matrix Reasoning since these tests (Visual Puzzles and Spatial Relations) are most similar in both content and task demands. In Visual Puzzles and Spatial Relations, the subject selects pieces of a puzzle that if put together would create the stimulus object. The created composite of Block Design and Visual Puzzles correlates with Visual Processing equally to the Perceptual Reasoning Index. Thus, the removal of Matrix Reasoning (which is supposed to be more of a measure of Fluid Intelligence) from the Perceptual Reasoning Index composite does not improve the correlation with Visual Processing as predicted. Unlike Picture Recognition which clearly differentiates itself from the other subtests, Matrix Reasoning is likely to measure more than one narrow ability. Regarding Fluid Intelligence correlates, the Concept Formation subtest is designed to measure the narrow ability of inductive thinking, and the Analysis-Synthesis subtest is designed to measure general sequential or deductive thinking. It was anticipated that Matrix Reasoning would have the strongest correlations with Concept Formation and Analysis-Synthesis, but this was not the case. Matrix Reasoning did correlate significantly with both Concept Formation and Analysis-Synthesis, but Block Design also correlated with both of these tests and had stronger correlations with each test as compared to Matrix Reasoning. Thus Block Design is also likely to be measuring multiple narrow abilities. In addition, there was an unexpected strong positive relationship between Visual Puzzles and Analysis-Synthesis. Again, these subtests are not likely to be measures of only one narrow ability. 7

8 The correlational patterns between the Perceptual Reasoning Index and the WJ-III COG Visual Processing and Fluid Intelligence subtests suggest that there is some overlap of the narrow abilities being measured. Thus the purity of Matrix Reasoning as a Fluid Intelligence subtest is questionable, since it correlates strongly with spatial perception; the purity of Block Design as a measure of Visual Processing is questionable, since it correlates strongly with both Fluid Intelligence subtests; the purity of Visual Puzzles as a measure of spatial relations and visualization is also questionable, since it correlates strongly with Analysis-Synthesis; and the purity of Analysis-Synthesis as a measure of general sequential reasoning, a narrow ability within Fluid Intelligence, is questionable since it correlates strongly with measures of visual processing. Taking into consideration the Working Memory Index and Short-Term Memory clusters, Arithmetic does not significantly correlate with Memory for Words and this is expected since Memory for Words is a measure of memory span/rote memory. Arithmetic and Digit Span do have significant correlations with Numbers Reversed, as all of these tests measure the narrow ability of working memory. Based on the results in Table 4, Arithmetic does significantly correlate with both Crystallized Intelligence tests (Verbal Comprehension and General Information) and Fluid Intelligence tests (Concept Formation and Analysis-Synthesis). This suggests that Arithmetic is not an isolated measure of working memory given that it is also associated with measures of crystallized intelligence and fluid reasoning. This is consistent with placement of Arithmetic under Fluid Intelligence as a measure of quantitative reasoning, but also the idea that Arithmetic is a measure of acquired knowledge associated with Crystallized Intelligence is compelling. This is consistent with McGrew s (2009) and Flanagan, et al. s (2009) formulation of the CHC structure of the where Arithmetic correlates with Fluid Intelligence, Crystallized Intelligence, and Short- Term Memory. Within the Processing Speed Index and Processing Speed cluster, Decision Speed does not correlate with any Perceptual Reasoning Index subtest, and this is expected since Decision Speed measures a different narrow ability (Speed of Reasoning). Coding and Symbol Search significantly correlate with Visual Matching as these tests do share the narrow abilities of rate-of-test taking and perceptual speed. There were unexpected patterns of correlations between the subtests of Arithmetic, Matrix Reasoning, Visual Puzzles and Block Design and the WJ-III COG subtests of Spatial Relations, Analysis-Synthesis, and Concept Formation. These patterns suggest that for both instruments, these subtests are more complex and not just a measure of one narrow ability. In addition, several of the subtests are correlating significantly with tests that are designed to represent different broad areas (e.g., Visual Processing versus Fluid Reasoning). One implication is that the CHC broad factors, which must be composed of two distinctly different narrow abilities, may not be as pure a measure of the process they purport to reflect. If the goal is to measure Gf, how do we know that we are not also measuring Gv? More practically, clinical interpretations of these broad areas and narrow abilities as specific processing deficits or strengths must take into account that many tests are multidimensional, and there may be several reasons why a person scores well or poorly on them. There are several limitations of this study. First, this is a pilot study and one obvious limitation is the small sample size. Another limitation is the fact that the examiners are still in a training program. In addition, there is absence of data regarding the ethnic status of the adults who were tested. It should also be noted that the does have several supplemental subtests (e.g., Figure Weights, a measure of Fluid Intelligence; Letter-Number Sequencing, a measure of Short-Term Memory). These subtests were not administered in this sample since the purpose of the study was to assess the degree to which the core subtests correlated to the WJ-III COG. Future studies in this area should investigate these relationships in larger and more varied samples (e.g., ethnic groups, age levels), and include all subtests. Overall, the findings of this study: (a) are consistent with much of the data on CHC relationships and do show that certain subtests are true measures of the narrow abilities they are designed to measure (e.g., Picture Recognition as visual memory, Memory for Words as memory span, etc.) and others are multidimensional (e.g., Arithmetic); and (b) contribute to the increasing knowledge of CHC broad and narrow abilities. References Carroll, J.B. (1993). Human cognitive abilities: A survey of factor analytic studies. New York: Cambridge University Press. Flanagan, D.P., Ortiz, S.O., & Alfonso, V.C. (2009). CHC Classifications. Retrieved from Horn, J.L. (1987). A context for understanding information processing studies of human abilities. In P.A.Vernon (Ed.), Speed of information-processing and intelligence (pp ). Norwood, NJ: Ablex. McGrew, K.S. (2009). What does the Measure. Retrieved from 8

9 McGrew, K.S. & Flanagan, D.P (1998). The Intelligence Test Desk Reference (ITDR): Gf-Gc cross-battery assessment. Boston: Allyn & Bacon. Schneider, W.J. (2010a). The Compositator. Retrieved from Schneider, W.J. (2010b). The Compositator: User s guide (Version 1.0). Woodcock-Munoz Foundation. Wechsler, D. (2008). Wechsler Adult Intelligence Scale-Fourth Edition. San Antonio, Texas: Pearson. Woodcock, R.W., McGrew, K.S., & Mather, N. (2001). Woodcock-Johnson-III Tests of Cognitive Abilities. Rolling Meadows, IL: Riverside. Woodcock, R.W., McGrew, K.S., Schrank, F.A., & Mather, N. (2007). Woodcock-Johnson-III normative update. Rolling Meadows, IL: Riverside. 9