Factor Analysis of the Korean Adaptation of the Kaufman Assessment Battery for Children (K-ABC-K) for Ages 2 ½ through 12 ½ Years

Transcription

1 K-ABC-K Factor Analysis 0 Running Head: K-ABC-K FACTOR ANALYSIS Factor Analysis of the Korean Adaptation of the Kaufman Assessment Battery for Children (K-ABC-K) for Ages 2 ½ through 12 ½ Years Note APA style is to double space everything, including the title page Soo-Back Moon, Ph.D. Catholic University of Daegu (South Korea) James E. McLean, Ph.D. East Tennessee State University Alan S. Kaufman, Ph.D. Yale University School of Medicine

2 K-ABC-K Factor Analysis 1 Running Head: K-ABC-K FACTOR ANALYSIS Factor Analysis of the Korean Adaptation of the Kaufman Assessment Battery for Children (K-ABC-K) for Ages 2 ½ through 12 ½ Years

3 K-ABC-K Factor Analysis 2 Abstract The K-ABC-K was developed to assess the intelligence and achievement of preschool and school-aged Korean children. This study examined the validity of the Sequential Processing, Simultaneous Processing, and Achievement scales of the K-ABC-K using the technique of principal factor analysis. The K-ABC-K is not just a simple translation, but an adaptation of the K-ABC for Korean children. The subjects of the study included 2,400 children from The K-ABC-K standardization sample, ranging in age from 2 ½ to 12 ½ years. Factor analysis of the 10 Mental Processing subtests for the 11 age groups produced two significant factors for each group: Sequential and Simultaneous. Joint analyses of the Mental Processing and Achievement subtests yielded three factors for ages 4 and above. As was true for the American K-ABC, only two factors emerged for ages 2 ½ and 3. In general, the factor analyses provided strong support for the construct validity of the K-ABC-K and supported common underlying mental constructs for Korean and American children.

4 K-ABC-K Factor Analysis 3 Factor Analysis of the Korean Adaptation of the Kaufman Assessment Battery for Children for Ages 2 ½ through 12 ½ Years The Kaufman Assessment Battery for Children-Korean (K-ABC-K; Moon & Byun, 1997) is an individually administered test of the intelligence and achievement of Korean children ages 2 ½ through 12 ½ years. The K-ABC-K is not merely a translation, but truly an adaptation of the K-ABC. Like the K-ABC, the definition of intelligence for the K-ABC-K rests on two types of mental processing (simultaneous and sequential). The K-ABC-K also includes an achievement scale as does the American K-ABC. Factor-analytic procedures are a commonly accepted approach for providing construct validity evidence for multiscale instruments (Anastasi & Urbina,1997) and have been used frequently for demonstrating construct validity for a variety of cognitive test batteries (Kaufman, 1975, 1994; Kaufman & Kaufman, 1983, 1993; Parker, 1983; Reynolds, 1979; Wechsler, 1991). Demonstrating the degree to which the factor structure of the K-ABC is constant or changes from one culture to another is important for interpreting the performance of children from diverse cultures. If the factor hyphen analytic results differ across culturally different groups, we cannot be confident that children who have different cultural backgrounds perceive and react to the stimulus material in the same manner; hence, cross-cultural comparisons may not be valid (Irvine & Carroll, 1980). Because the theoretical definition of intelligence for the K-ABC rests on the distinction between two types of mental processing (sequential and simultaneous), it was extremely important to show that exactly two factors underlie the K-ABC Mental Processing Composite, and that these dimensions correspond closely to the assignment of

5 K-ABC-K Factor Analysis 4 the subtests to either the Simultaneous Processing or Sequential Processing Scale. In addition, the three-scale format of the K-ABC demands that factor-analytic evidence of the existence of the Achievement dimension (Kaufman & Kaufman, 1983) when the achievement subscales are included. Principal components analysis and principal factor analysis of the American K- ABC were conducted for the Mental Processing subtests alone and also for all subtests at each year for ages between 2½ and 12½, using data from the 2,000 standardization sample cases (Kamphaus, Kaufman, & Kaufman, 1982). When only the Mental Processing subtests were analyzed, there was clear-cut empirical support for the existence of two and only two factors at each age level. Furthermore, orthogonal rotation of these factors for each group produced obvious Simultaneous and Sequential dimensions. When the achievement subscales were added, principal components analysis and principal factor solutions revealed that only two factors should be interpreted for ages 2 ½ and 3, however, three factors produced the most sensible reduction of the data for ages 4 and above (Kamphaus, et al.). The two factors for ages 2½ and 3 were best labeled Sequential Processing and Simultaneous Processing /Achievement. For ages 4 through 12 ½, the three factors were clearly interpretable as Simultaneous Processing, Sequential Processing, and Achievement. Wilson, Reynolds, Chatman, and Kaufman (1983) conducted confirmatory factor analysis of the K-ABC for the 11 standardization age groups. Two factor solutions were analyzed for the Mental Processing subtests and three-factor solutions for all K-ABC subtests combined. The Sequential-Simultaneous dichotomy was confirmed for all age

6 K-ABC-K Factor Analysis 5 groups, and the Sequential-Simultaneous-Achievement organization of the K-ABC subtests was also confirmed for all ages, including 2 ½ -and 3-year-olds. Developing a foreign version of any standardized test requires more than the translation of items and instructions of the test into another language, it necessitates adaptation of the test for use with the target population. Differences between the Korean version of the Kaufman Assessment Battery for Children (K-ABC-K) and the American K-ABC include differences in items and item order in subtests, however it keeps the theory-based dichotomy of the Sequential and Simultaneous Processing Scales, and it includes a separate Achievement Scale. For the Korean version, changes in the American K-ABC were made based on data with a cross-cultural validity study of the K-ABC with Korean Children (Moon, 1988), along with cultural and linguistic considerations. Like the K-ABC, the K-ABC-K consists of 16 subtests: three Sequential, seven Simultaneous, and six Achievement. The age range of the K-ABC-K is from 2 ½ to 12 ½ years to match the K-ABC. The purpose of this study was to explore the factor structure of the K-ABC-K and assess (a) the existence of sequential and simultaneous factors across the age range, and (b) the emergence of a separate achievement dimension that corresponds in make-up to the K-ABC-K achievement scale. Method Sample A national standardization program was conducted between January 1996 and August 1997, when more than 2400 children were tested at 48 sites in 24 geographic regions of the Republic of Korea (South Korea). The stratified multistage sampling

7 K-ABC-K Factor Analysis 6 procedure was designed to ensure a nationally representative norm group of children ages 2 ½ through 12 ½. Sampling was based on the most recent population reports from the 1995 Korean Census. The sample was stratified within each age group by gender, geographic region, community size, and educational placement of the child. Socioeconomic status was not considered since criteria are not available in Korea to determine socioeconomic status. Instrument In a cross-cultural validity study of the K-ABC with Korean children (Moon, 1988), several items of K-ABC Sequential and Simultaneous Scales were found to be biased against either Korean or American children. Item bias was tested using Angoff's transformed item-difficulty or delta-plot method (Angoff & Ford, 1973). Item-difficulty values (p-values) for the American sample and the Korean sample were calculated. Each p-value was then transformed using a normal curve-area table to normal deviates and transformed from the normal deviates to delta-values using a linear transformation. The delta values obtained in two groups were plotted on a bivariate graph (Angoff, 1982; Jensen, 1980). Deviations of each item from the major axis of the bivariate plot were direct indications of the extent to which the items had different difficulties in the two groups. A large deviation from the major axis was taken as evidence of bias for that item. Finally, the perpendicular distance values of the items were tested at the.01 level to assess the statistical significance of each item's deviation from the major axis. No item from the Sequential Processing subtests was found to be biased against either Korean or American children, but six items from Simultaneous Processing subtests were biased against either Korean or American children. In an examination of the

8 K-ABC-K Factor Analysis 7 absolute values of the perpendicular distances among the Sequential Processing subtests, ranges were observed between.03 and 1.32 for Hand Movements,.00 and 1.10 for Number Recall, and.01 and 1.97 for Word Order. The range of perpendicular distance values from the Simultaneous Processing items was between.05 and 3.35 for Magic Window,.02 and.99 for Triangles,.00 and 2.30 for Matrix Analogies,.07 and 1.41 for Spatial Memory, and.09 and 1.19 for Photo Series. Based on these results, three items from the Mental Processing subtests were found to be significantly biased in favor of American children (p <.01) due to cultural bias or verbal labeling differences. These were Item 12 (saw) in Magic Window and Items 7 (camel) and 17 (stove) in Gestalt Closure. Item 14 (watch) in Magic Window, Item 1 in Face Recognition, and Item 5 (camera) in Gestalt Closure were found to be biased in favor of Korean children. Based on these results, three items from the Mental Processing subtests were changed to work properly for Korean children and all items in each subtest were reordered according to the estimated item difficulties in the K-ABC-K. Number Recall and Arithmetic subtests were found to be too easy for Korean children. Several new, more difficult items were added to the subtest. Following this, the test demonstrated an adequate ceiling for older Korean children. All items from the K-ABC Reading Decoding subtest were eliminated and replaced with newly developed ones based on careful linguistic considerations. Thirteen (35%) of the 35 Faces & Places items were replaced by newly developed ones because they were geared toward cultural experiences in the United States (Kaufman & Kaufman, 1983). The K-ABC-K yields normalized standard scores with a mean of 100 and a standard deviation of 15 for the Mental Processing Scales (Sequential Processing,

9 K-ABC-K Factor Analysis 8 Simultaneous Processing, and Mental Processing Composite) and the Achievement Scale. Standard scores with a mean of 10 and a standard deviation of 3 are provided for each Mental Processing subtest. The Achievement subtests yield standard scores with the same parameters as the global scales. Like the K-ABC, the K-ABC-K offers a Nonverbal Scale--a special combination of Mental Processing subtests with a mean of 100 and a standard deviation of 15. The K-ABC-K Manual (Moon & Byun, 1997) offers evidence to support the test's psychometric properties. Reliability coefficients for the scales and subtests are good with mean split-half reliability coefficients for the global scales ranging from.87 (Sequential) to.92 (Mental Processing Composite) for preschool children and from.91 (Sequential) to.96 (Achievement) for school-age children. Mean split-half coefficients for the Mental Processing and Achievement subtests ranged from.79 to.95 (median =.84) for preschool children and from.78 to.94 (median =.89) for school-age children. Construct and concurrent validity of the K-ABC-K are also documented in the Manual. Age differentiation in raw score was one criterion used to validate the K-ABC-K. Mean raw scores and standard deviations on each subtest of the 11 age groups showed steady increases across the entire age range for every subtest of the K-ABC-K. Procedure Partial intercorrelations (partialing out the effect of age) among the raw scores on the K-ABC-K Mental Processing subtests were computed for each of 11 age groups. These matrices were 5 x 5 for ages 2 ½ through 3, 7 x 7 for ages 4 through 5, 8 x 8 for ages 6 through 12 ½. Each matrix was subjected to a principal components analysis (value of 1 in diagonals, no iterations, followed by varimax rotation of all factors with

10 K-ABC-K Factor Analysis 9 eigenvalues of 1.0 or above) to help determine the appropriate number of factors for each of 11 age groups. Then principal factor analysis was performed for each age group, with R squared in diagonals as the initial estimates of communality. Iterations were performed and two-factor, three-factor, and four-factor varimax rotated solutions were examined. The scree test (Cattell, 1966) and psychological meaningfulness of the various varimax-rotated principal factor analysis was applied to determine the preferred number of factors for each age group. Finally, partial correlations (partialing out the effect of age) among the raw scores on the K-ABC-K subtests (Mental Processing and Achievement) were obtained for each of the 11 age groups. These matrices ranged from 7 x 7 for ages 2 ½, 9 x 9 for ages 3, 11 x 11 for ages 4 through 5, 12 x 12 for ages 6, and 13 x 13 for ages 7 through 12 ½. The same factor analytic procedures applied to the Mental Processing subtests were also applied to these correlation matrices. Results Mental Processing Subtests Only Principal components analysis of K-ABC-K Mental Processing subtests alone at 11 age levels between 2 ½ and 12 ½ years produced two significant components for all 11 age groups, using the eigenvalue equal to or greater than 1.0 criterion. Then principal factor analysis was conducted for each age group, with squared R in diagonals as the initial communality estimates. The preferred number of factors for each age group was based both on the number of significant components identified by Cattell s (1966) scree test and psychological meaningfulness of the various principal factor solutions. Cattell s (1966) scree test indicated that two would be the most appropriate number of factors to rotate for each group. This finding, plus examination of the one-

11 K-ABC-K Factor Analysis 10 factor and three-factor rotated solutions for each of 11 age groups, made it clear that the two-factor solution produced the most meaningful reduction of the data. Tables 1 and 2 summarize the results of the principal factor analyses of the Mental Processing subtests by age group. [Please insert Tables 1 and 2 about here.] As shown in Tables 1 and 2, clearly identifiable Sequential and Simultaneous factors emerged at each age group. The Sequential Processing subtests had the highest factor loadings on the Sequential factor(.40 to.84), just as the Simultaneous Processing subtests invariably had the strongest mean loadings on the Simultaneous factor (.36 to.79 ). Thus, the factor analysis of the Mental Processing Subtests strongly supported the construct validity of the Sequential and Simultaneous Processing Scales on the K-ABC-K. Mental Processing and Achievement Subtests Combined Principal components analysis of all K-ABC-K subtests at the 11 age levels between 2 ½ and 12 ½ produced three significant components for ages 4 and above, and two significant components for ages 2 ½ and 3, using the eigenvalue equal to or greater than 1.0 criterion. The preferred number of factors for each age group was based both on the number of significant components identified by Cattell's scree test and psychological meaningfulness of the various principal factor solutions. The scree test (Cattell, 1966) and examination of psychological meaningfulness of one-factor, two-factor, three-factor, and four-factor solutions were used to determine the most meaningful and appropriate number of factors to be rotated. Tables 3 and 4 provide group-by-group factor solutions resulting from the joint analyses of the Mental Processing and Achievement subtests.

12 K-ABC-K Factor Analysis 11 [Insert Tables 3 and 4 about here.] At ages 2 ½ - 3, only two meaningful factors emerged. Whereas the factor labeled Sequential might be called Sequential/Achievement, it was assigned the former name because the pattern of loadings of five Mental Processing subtests resembled closely the pattern observed for the Sequential factor in the previous analysis (see Tables 1 and 2). At age 2 ½, Expressive Vocabulary (.69) and Faces and Places (.66) loaded substantially only on the Sequential Processing factor. Also, at age 3, Expressive Vocabulary (.64), Faces and Places (.65), Arithmetic (.66), and Riddles (.63) loaded strongly on the Sequential Processing dimension. At ages 4 and above, the first factor was clearly identified as Sequential across all age groups, with Number Recall and Word Order evidencing the highest loadings for each age group (.46 to.77). Interpretation of the second and third factors was not complicated. At ages 4 and above, the second factor was identified as Simultaneous and the third factor as Achievement. All Simultaneous subtests had their highest loadings (.40 to.78) on the Simultaneous factor. The Achievement subtests had their strongest loadings (.36 to.80) on the Achievement factor in most analyses. The third factor can be called Achievement since most Achievement subtests had their highest loadings on the third factor. Discussion Mental Processing Subtests Only These results are consistent with those of the K-ABC factor analysis reported by Kaufman and Kamphaus (1984). They found that in the two-factor solution of the K- ABC Mental Processing subtests, mean loadings of the Sequential Processing subtests on

13 K-ABC-K Factor Analysis 12 the Sequential factor ranged from.43 to.75 and the Simultaneous Processing subtests loaded on the Simultaneous dimension with values between.40 and.69. These loadings are slightly lower than those of the K-ABC-K Mental Processing subtests across the age groups. Principal factor analyses of the K-ABC-K Mental Processing subtests therefore offer strong support for the construct validity of the K-ABC-K, as well as for the placement of each preschool and school-age subtest on its respective scale. Mental Processing and Achievement Subtests Combined Kaufman and Kamphaus (1984) also found two meaningful factors for ages 2 ½-3 in the joint factor analysis of Mental Processing and Achievement subtests. However Achievement and Simultaneous subtests had their substantial loadings on the same factor labeled as a Simultaneous/Achievement factor. Based on these results, Korean children aged 2 ½-3 years seem to handle the stimuli of Achievement subtests by Sequential processes, whereas American Children process the Achievement subtests by Simultaneous processing. These cultural-bound differences stimulate very interesting speculations that Korean children under age 3 might be more dominated by Sequential processing to handle various stimuli, whereas American children under age 3 prefer to use Sequential processing to handle factual stimuli. These results are in line with the results of Moon, Byun, McLean, and Kaufman s (1994) comprehensive study conducted to examine the simultaneous-sequential profile of Korean children for ages 2 ½-12 ½ and to test the generalizability of Lynn s (1987) hypothesis that posits a genetically programmed superiority in visual-spatial ability for Oriental nationalities. It was found that a high sequential-low simultaneous profile emerged consistently across all age groups. These findings were contrary to that found for Japanese children who

14 K-ABC-K Factor Analysis 13 demonstrated a high simultaneous-low sequential profile (Ishikuma et al, 1988; Kaufman et al., 1989). The Kaufman Assessment Battery for Children-Spanish (K-ABC-S) was developed to assess the intelligence and achievement of preschool and school-age Hispanic children. As with the K-ABC-K, the K-ABC-S is an adaptation of the K-ABC rather than merely a translation. Moon et al. (1989) examined the validity of the Sequential Processing, Simultaneous Processing, and Achievement scales of the K-ABC- S using the technique of principal factor analysis. The subjects comprised the 979 children in the K-ABC-S standardization sample, ranging in age from 3 to 12 ½ years. Factor analysis of the 10 K-ABC-S Mental Processing subtests for five age groups produced two significant factors for each age group: Sequential and Simultaneous. Joint analyses of the Mental Processing and Achievement subtests yielded three factors for ages 5 and above. As was true for the American K-ABC, only two factors emerged for ages 3 and 4. The same pattern of factor loadings was found for Black children (Reynolds & Wilson, 1984) and for Korean children (Moon, 1988). For the present study, all the K-ABC-K subtests loaded higher on their designated factor, in most cases, much higher. However, a developmental trend was clearly in evidence for Hand Movements. For ages 2 ½ through 6, this subtest enjoyed significant loadings only on the Sequential Factor. At age 7, a sudden shift occurred and this subtest loaded significantly on both mental processing dimensions (loading of.51 and.38 on Sequential and Simultaneous processing, respectively). After age 7, Hand Movements showed its substantial loadings only on the Sequential dimension.

15 K-ABC-K Factor Analysis 14 These developmental trends for Hand Movements in the K-ABC-K are consistent with those of the K-ABC reported by Kaufman and Kamphaus (1984). They found that for ages 2 ½-4, Hand Movements was strongly associated with the Sequential factor but at ages 5-12 ½ this subtest became about equally dependent upon both mental processes. Several explanations for the developmental trend of the Hand Movements subtest are possible. It is possible that both processes are required for success, or perhaps school-age children are able to apply either approach for efficient handling of the stimuli. Another possible explanation is that longer series of movements are best recalled by a simultaneous approach, whereas shorter series (which characterize virtually all items for preschoolers) are best handled by sequential processing (Kaufman & Kamphaus, 1984). An Achievement factor emerged at each age beginning with 4 years. A developmental trend was clearly in evidence for the Arithmetic subtest. For ages 2 ½ through 6, this subtest showed significant loadings on the Achievement factor as well as on the Sequential dimension ( ). At ages 8 through 11 this subtest had significant loadings both on the Achievement and Simultaneous factors. For age 12, this subtest again had substantial loadings on the Achievement factor and the Sequential dimension. This trend for the Arithmetic subtest indicates that the processing skills required for success on the K-ABC-K Arithmetic subtest were about as important as its acquired knowledge component. In the case of Reading Decoding, for ages 5 through 7 this subtest had substantial loadings on the Achievement factor as well as on the Sequential factor. Riddles loaded significantly on the Simultaneous factor for ages 11 and above. In all, Achievement subtests tended to have higher loadings on the Sequential factor at the preschool ages, and again at age 12, but these subtests generally loaded

16 K-ABC-K Factor Analysis 15 higher on the Simultaneous dimension for children ages 7-11 years. These findings are quite consistent with the results of the factor analysis of the American K-ABC (Kaufman and Kamphaus, 1984), and with Piaget s theory of cognitive development. Preoperational children often cannot de-center and focus on more than one aspect of a problem-solving situation at a time (Piaget, 1950), perhaps encouraging a sequential processing approach to school-related problems. Similarly, the simultaneous learning of the concrete operational child is consistent with the emerging cognitive structures of these youngsters that are especially geared to integrate, in parallel fashion, stimuli in their environment (Kaufman & Kamphaus, 1984). Whereas it is the preoperational child s limitations that might foster an overemphasis on sequential processing, it is the newly developing asset of the formal operational child that can lead to this same result. These children s thought processes are characterized by combinational analysis, the systematic (sequential) scientific method, hypothesis generation and testing, and propositional thinking (Inhelder & Piaget, 1958; Piaget, 1950). In that Achievement subtests also had meaningful loadings on one or both processing dimensions, it is important to note that the Mental Processing tasks consistently did not have substantial factor loadings on the Achievement dimension. These data provided strong support for the validity of the Achievement construct in the K-ABC-K. Summary The factor analyses of the K-ABC-K for the Mental Processing subtests provide strong support for the construct validity of the Sequential and Simultaneous dimensions of the battery. In addition, the factor analyses of all the K-ABC-K subtests support the

17 K-ABC-K Factor Analysis 16 three-factor structure (Sequential/Simultaneous/Achievement) at ages 4 and above, but do not support it at ages 3 and below. At ages 3 and below, the Mental Processing and Achievement factors were less distinct for Korean children than for American children. The Achievement subtests loaded significantly on the first factor (Sequential). These findings are line with the factor structure of the K-ABC for Mexican children (Moon et al., 1989). This study adds evidence of the construct validity of the K-ABC across cultures. The two- and three-dimension results hold for Korean and Hispanic children as well as American children. Since the factor analytic results are consistent across multiple cultures, we can be confident that children from different cultural backgrounds perceive and react to the stimulus material in the same manner, thus supporting the cross-cultural use of instruments such as the K-ABC.

18 K-ABC-K Factor Analysis 17 References Analstasi, A., & Urbina, S. (1997). Psychological testing (7 th ed.). New York: Macmillian. Cattell, R. B. (1966). The scree test for the number of factors, Multivariate Behavioral Research, 1, Gunnison, J. A. (1984). Developing educational intervention from assessment involving K-ABC. The Journal of Special Education, 18, Inhelder, J. L., & Piaget, J. (1958). The growth of logical thinking from childhood to adolescence, New York: Basic Books. Irvine, S. H., & Carroll, W. K. (1980). Testing and assessment across cultures: Issues in methodology and theory. In H. C. Triandis. W. Berry (Ed.), Handbook of crosscultural psychology: methodology (vol.2) (pp ). Boston: Allyn & Bacon. Ishikuma, T., Moon, S. B., & Kaufman, A. S. (1988). Sequential-simultaneous analysis of Japanese children s performance on the Japanese McCarthy. Perceptual and Motor Skills, 66, Kamphaus, R. W., Kaufman, A. S., & Kaufman, N. L. (1982, August). A crossvalidation study of sequential-simultaneous processing at ages 2 ½ - 12 ½ using the Kaufman Assessment Battery for Children (K-ABC). Paper presented at the meeting of the American Psychological Association, Washington, DC. Kaufman, A. S. (1994). Intelligence Testing with WISC-III. New York: Wiley. Kaufman. A. S. (1975). Factor analysis of the WISC-R at 11 age levels between 6 ½ and 16 ½ years. Journal of Counseling and Clinical Psychology, 43, Kaufman, A. S., & Kamphaus, R. W. (1984). Factor analysis of the Kaufman Assessment Battery for Children. Journal of Educational Psychology, 76,

19 K-ABC-K Factor Analysis 18 Kaufman, A. S., McLean, J. E., Ishikuma, T., Moon, S. B. (1989). Integration of the literature on the intelligence of Japanese children and analysis of the data from a sequential-simultaneous model. School Psychology International, 10, Kaufman, A. S., & Kaufman, N. L. (1983). Interpretation manual for the Kaufman Assessment Battery for Children. Circle Pine, MN: American Guidance service. Kaufman, A. S., & Kaufman, N. L. (1993). Manual for the Kaufman Adolescent & Adult Intelligence Test. Circle Pine, MN: American Guidance Service. Lynn, R. (1987). The intelligence of the Mongoloids: A psychometric, evolutionary and neurological theory. Personality and Individual Difference, 8, Moon, S. B. (1988). A Cross-cultural validity study of the Kaufman Assessment Battery for Children with Korean Children, Unpublished doctoral dissertation. The University of Alabama, Tuscaloosa. Moon, S. B., Kaufman, A. S., & Ishikuma, T. (1989). Factor analysis of the Kaufman Assessment Battery for Children-Spanish(K-ABC-S) for age 3 through 12 ½ years, Paper presented at the Annual Meeting of Mid-South Educational Research Association, Little Rock, Arkansas. Moon, S. B., & Byun, C. J. (1997). Interpretation manual for the Kaufman Assessment Battery for Children-Korean, Hakjisa, Seoul, Korea. Moon, S. B., Byun, C. J, McLean, J. E., & Kaufman, A. S. (1994). Sequential- Simultaneous Profile Analysis of Korean Children s performance on the Kaufman Assessment Battery for Children. Research in the Schools, 1(2), Parker, K. (1983). Factor analysis of the WAIS-R at nine age levels between 16 and 74 years. Journal of counseling and Clinical Psychology, 51,

20 K-ABC-K Factor Analysis 19 Piaget, J. (1950). The psychology of intelligence, New York: Harcourt Brace. Reynolds, C. R. (1979). Factor structure of the Peabody Individual Achievement Test at five grade levels between grades one and twelve. Journal of School Psychology, Reynolds, C. R., & Wilson, V. L. (1984, August). Factor structure of the K-ABC for blacks and whites from the standardization sample. Paper presented at the meeting of the American Psychological Association, Toronto, Ontario. Wilson, R. L., Reynolds, C. R., Chatman, S., & Kaufman, A. S. (1983, March). Confirmatory analysis of simultaneous, sequential, and achievement factors on the K-ABC. Paper presented at the meeting of the National Association of School Psychologists, Detroit, MI. Wechsler, D. (1991). Manual for the Wechsler Intelligence Scale for Children-Third Edition (WISC-III). San Antonio: The Psychological Corporation.

21 K-ABC-K Factor Analysis 20 Table 1. Varimax-Rotated Loadings of K-ABC-K Mental Processing Subtests for Ages 2½ - 6 Subtests 2 ½ SQ SM SQ SM SQ SM SQ SM SQ SM Sequential Processing 3. Hand Movements Number Recall Word Order Simultaneous Processing 1. Magic Window Face Recognition Gestalt Closure Triangles Matrix Analogies Spatial Memory Photo Series Note. K-ABC-K=Korean Version of Kaufman Assessment Battery for Children; SQ=Sequential; SM=Simultaneous. Loadings of.35 and above are underlined.

22 K-ABC-K Factor Analysis 21 Table 2. Varimax-Rotated Loadings of K-ABC-K Mental Processing Subtests for Ages 7-12 ½ Subtests SQ SM SQ SM SQ SM SQ SM SQ SM SQ SM Sequential Processing 3. Hand Movements Number Recall Word Order Simultaneous Processing 1. Magic Window 2. Face Recognition 4. Gestalt Closure Triangles Matrix Analogies Spatial Memory Photo Series Note. K-ABC-K=Korean Version of Kaufman Assessment Battery for Children; SQ=Sequential; SM=Simultaneous. Loadings of.35 and above are underlined.

23 K-ABC-K Factor Analysis 22 Table 3. Varimax-Rotated Loadings of K-ABC-K Sequential, Simultaneous, and Achievement Factors in Analysis of All K-ABC-K Subtests for Ages 2 ½ ½ Subtests SQ SM SQ SM SQ SM AC SQ SM AC SQ SM AC Sequential Processing 3. Hand Movements Number Recall Word Order Simultaneous Processing 1. Magic Window Face Recognition Gestalt Closure Triangles Matrix Analogies Spatial Memory Photo Series Achievement 11. Expressive Vocabulary Faces & Places Arithmetic Riddles Reading Decoding Reading Understanding Note. K-ABC-K=Korean Version of Kaufman Assessment Battery for Children; SQ=Sequential; SM=Simultaneous. AC=Achievement. Loadings of.35 and above are underlined.

24 K-ABC-K Factor Analysis 23 Table 4. Varimax-Rotated Loadings of K-ABC-K Sequential, Simultaneous, and Achievement Factors in Analysis of All K-ABC-K Subtests for Ages 7-12 ½ ½ Subtests SQ SM AC SQ SM AC SQ SM AC SQ SM AC SQ SM AC SQ SM AC Sequential Processing 3. Hand Movements Number Recall Word Order Simultaneous Processing 1. Magic Window Face Recognition Gestalt Closure Triangles Matrix Analogies Spatial Memory Photo Series Achievement 11. Expressive Vocabulary 12. Faces & Places Arithmetic Riddles Reading Decoding Reading Understanding Note. K-ABC-K=Korean Version of Kaufman Assessment Battery for Children; SQ=Sequential; SM=Simultaneous. AC=Achievement. Loadings of.35 and above are underlined.