Analysis: Historical & Theoretical Basis of Assessment
In 1979, Nadine Kaufman laid the foundation for the development of the KABC.
Kaufman (1979) stated that, “Individual intelligence testing has been remarkably resistant to change, despite advances in the related fields such as psychology and neurology” (p.96).
Kaufman intelligent testing philosophy was largely based on Wesman`s (1968) treatise on intelligence. Kaufman gave great emphasis to the need for a theory driven assessment and interpretation of children`s intelligence. The KABC is based on research and theory from a variety of areas. The principal areas that were evaluated and interpreted by the Kaufman`s were clinical neuropsychology (Luria, 1976), cerebral specialization (Bogen, 1975; Sperry, 1976) and cognitive psychology (Neisser, 1976). While relying on these areas and theories, the KABC represents the Kaufmans` unique theory of sequential and simultaneous processing that does not completely correspond with those of Luria, Sperry, and Neisser. It was Kaufman`s assessment experience as a psychologist that was critical in developing the child-centered nature of the KABC.
The emphasis on assessing intelligence from a strong theoretical basis is an important strength of the KABC. The KABC scales are based upon a model of sequential and simultaneous information processing. Sequential processing emphasizes the arrangement of stimuli in sequential order in order to correctly solve a problem. In each case, stimuli are linearly or temporarily related to the previous one, creating a serial interdependence (Kaufman & Kaufman, 1983).
Compare the Assessment Tool with Similar Tools
Validity in relation to other assessment tools
The KABC-II manual (Kaufman & Kaufman, 2004), indicates strong construct validity. Scale indexes (Sequential/Gsm, Simultaneous/Gv, Learning/Glr, & Knowledeg/Gc) intercorrelate to a moderate degree at the preschool level. At age 4, correlation coefficients were lowest among Sequential/Simultaneous (r=.44), Sequential/ Learning (r=.44), Simultaneous/Learning (r=.45), and Learning/Knowledge (r=.49). The scale indexes that correlated highest were Simultaneous/Knowledge (r=.60) and Sequential/Knowledge (r=.55). At age 5, Learning/Knowledge (r=.49) correlated to the lowest degree. All other pairs were moderately correlated, with values ranging from .52 to .55. Moreover, factor analysis studies using standardization data revealed evidence for distinct factors in the areas of Sequential/Gsm and Learning/Glr among 4-year-old examinees. At this age, however, the abilities of Knowledge/Gc and Simultaneous/Gv were highly correlated and did not represent significantly different factors, due to the Concept Formation subtest, which loaded heavily on both scales. The test authors chose to include both the Knowledge and Simultaneous scales in the final battery, however, given that the content is clearly different. At the age of 5, all abilities were found to be distinct factors except for Simultaneous/Gv and Planning/Gf. Because factor analyses showed these scales do not become differentiated until the age of 7, the Planning/Gf factor was not included within the battery for children ages 3-6.
Reliability in relation to other assessment tools
Though not yet studied as extensively ass other cognitive measures due to its newer release date, the KABC-II demonstrates good reliability. In the KABC-II Manual, Kaufman and Kaufman (2004) reported a split-half reliability coefficient of .96 among 4-year-old participants and 097 among 5-year-old participants on the Fluid-Crystallized Index (FCI).
Other reliability coefficients included .91 (age 4) and .90 (age 5) on Sequential/Gsm, 088 (age 4) and 093 (age 5) on Simultaneous/Gv, .89 (age 4) and .91 (age 5) on Learning/Glr, and .92 (age 4) and .90 (age 5) on Knowledge/Gc. Test-retest reliability statistics also were calculated in three age ranges (3-5, 7-12, and 13-18), with an average of four weeks between administration. The adjusted FCI coefficient for the 3 to 5 age group was .90. Moreover, adjusted correlations on the factor scales ranged from .74-.93 (Kaufman & Kaufman, 2004).
Norms in relation to other assessment tools
According to the authors of the Kaufman Assessment Battery for Children (KABC: Kaufman & Kaufman, 2005) the test “measures intelligence” defined as “an individual’s style of solving problems and processing information” (2005, p. 2). The K-ABC also differed from many other intelligence batteries of the time by designing subtests for specific age groups, with preschool children being administered fewer activities than school-aged children. The Sequential Processing and Simultaneous Processing indexes combined to produce a “global” scale of intelligence, the Mental Processing Composite (MPC). Moreover, a nonverbal scale was included on the K-ABC, making the test a popular choice to use with children who have speech or language disorders, are hearing impaired, are bilingual, or do not speak English. In addition to the cognitive indexes, the K-ABC included a separate achievement scale, designed to measure knowledge acquisition (Kamphaus, 2001).
Measures of Central Tendency in relation to other assessment tools
The K-ABC is comprised of a Sequential scale, a Simultaneous scale, Mental Processing Composite and an Achievement scale. In the K-ABC, it is neither the modality of presentation nor the modality of response that determines in which scale (sequential or simultaneous) the individual subtests are placed. Instead, it is the form of mental processing that is required which is the most salient feature of a task that determines its placement on subscale of the K-ABC.
These two methods of information processing (sequential and simultaneous) are often interacting but one approach usually is the primary mode of processing (Kaufman & Kaufman, 1983). The K-ABC assumes that when the processing style of the individual does not coincide with the processing demands of a task, the mismatch causes a negative impact on performance.
Another important component of the K-ABC is the Achievement scale measures what has been traditionally viewed as verbal intelligence (vocabulary, verbal concept formation, and acquired school skills such as reading arithmetic, and sentence comprehension). Performance on the K-ABC Achievement scale is considered to be an estimate of a child’s ability to apply his mental processing skills to the acquisition of knowledge from the environment (Kaufman, Kaufman, & Kamphaus, 2005). While it is difficult to distinguish between what a child knows (achievement) from how well the child solves problems and engages than most comparable and provides a valuable assessment instrument that can be used to identify children with learning disabilities (Kaufman & Kaufman, 2003).
Determine & Summarize Appropriate Use of Tool
This intelligence scale consists of subtests that are combined to form scales of Sequential, Simultaneous, and the Mental Processing Composite (MPC). The MPC is considered to be a summary score that reflects an individual’s sequential and simultaneous processing abilities. On a separate Achievement scale, subtests are combined to form a global achievement score.
The K-ABC also has an alternate Nonverbal scale that can be administered in pantomime to children with speech- language handicaps, hearing impairments, and those with limited or no English skills. Responses to test items are given motorically. The Nonverbal scale serves as a general estimate of intelligence and cannot be subdivided into sequential and simultaneous processing scales.
All of the global scales (Sequential, Simultaneous, Mental Processing, and Achievement) have a mean standard score of 100 with a standard deviation of 15. Since a common metric is use, scores on each scale can be compared including comparisons between mental processing and achievement for children suspected of having a learning disability. Additionally, by using this metric, scores on the K-ABC can be compared with other standardized tests of intelligence and achievement that use similar metric and standardization samples (Reynolds, 1994).
The average administration time is 25 to 55 minutes for the core battery, Luria Model and 35to 70 minutes for core battery, CHC model.
The K-ABC is made up of 16 subtests, not all of which are administered to any age group. Children ages 2½ are given subtests, age 3 receives nine subtests, ages 4 and 5 are administered eleven subtests (but not exact same subtests due to developmental changes), and thirteen subtests are given to children ages 7 through 12 ½. Time needed to administer the K-ABC varies from approximately thirty minutes for 2½ year olds up to one hour and twenty minutes for 7 to 12 ½ year olds.
Modeled after the Wechsler scales, the individual Mental Processing subtests yield a mean standard score of 10 with a standard deviation of 3. The Achievements subtests have a mean score of 100 and a standard deviation of 15. This allows for comparisons of global scale scores with individual achievement areas.
This intelligence scale consists of subtests that are combined to form scales of Sequential, Simultaneous, and the Mental Processing Composite (MPC). The MPC is considered to be a summary score that reflects an individual’s sequential and simultaneous processing abilities. On a separate Achievement scale, subtests are combined to form a global achievement score.
The K-ABC also has an alternate Nonverbal scale that can be administered in pantomime to children with speech- language handicaps, hearing impairments, and those with limited or no English skills. Responses to test items are given motorically. The Nonverbal scale serves as a general estimate of intelligence and cannot be subdivided into sequential and simultaneous processing scales.
All of the global scales (Sequential, Simultaneous, Mental Processing, and Achievement) have a mean standard score of 100 with a standard deviation of 15. Since a common metric is use, scores on each scale can be compared including comparisons between mental processing and achievement for children suspected of having a learning disability. Additionally, by using this metric, scores on the K-ABC can be compared with other standardized tests of intelligence and achievement that use similar metric and standardization samples (Reynolds, 1994).
Distinguish Strength & Weakness of Tool
Strengths and weaknesses of the test in processing new information, identified through task analysis of a student`s protocol are used to define parameters and focus of educational intervention based on the K-ABC. Interventions developed from the programs based on the sequential-simultaneous model of information processing are not deficit based. Academic interventions are designed based on child`s strengths, or in other words, their preferred mode of achieving, retaining, transferring and organizing information.
The scores in KABC-II provide information that can be used in the development of educational interventions (Kaufman & Kaufman, 2005). The KABC was probably the first standardized test for which clinically relevant goals were combined with acceptable psychometric properties such as a large national, representative sample.
Suitability & Effectiveness of Tool for Special, Ethnic and Culturally Diverse Populations
The K-ABC has been recommended for children from diverse ethnic groups. Although research has investigated the validity of this instrument, little information is available regarding its stability over time. Stability or the consistency of scores from one time to another is an important indicator of the technical adequacy of an intelligent test. Additionally, it is important that these scores remain stable over time since critical decisions regarding educational programming are based upon them.
Previous research has indicated that intelligence test performance is quite stable, especially during the school-age years and beyond (Cohen, Swerdlik, & Phillips, 1996). Two variables that are most highly related to the stability of intelligence scores are the age of the children at the time of they were first tested and the interval between test administrations. Generally, it has been found that the older the children are at the initial testing and the shorter the test interval between tests, the more stables the scores (Kamphaus, 1993). Research findings regarding the stability of cognitive abilities of preschoolers have been somewhat inconclusive. Some authors have taken the position that intelligence test scores do not achieve stability prior to the age of 5 (Cohen, Swerdlik, & Phillips, 1996; Kamphaus, 1993). More recently, other researchers have found that some intelligence scores obtained as early as age 3 are relatively stable (Bracken & Walker, 1997). The K-ABC manual cites test-retest reliability for an interval of 2-4 weeks for a sample of preschool and school-aged children. Scores were found to be highly stable for this short interval, with correlation coefficients ranging from .83 to .97 for the global scales (Kaufman & Kaufman, 1983).
Conclusions
In general, the KABC is a necessary instrument to effectively assess intelligence and achievement:
∙ theory based assessment of process not just product
∙ consideration of multicultural issues and sensory impairments with representatives of
various disabilities, cultures, and languages represented in the standardization sample
∙ the ability of an instrument to translate scores into meaningful classroom
recommendations and remediation techniques
∙ stability of test scores for the children most often assesses (e.g., learning disabled) over
a time period often seen in practice (e.g., three-year comprehensive reevaluation for
learning disabled).
The KABC has made important contributions to the fields of intellectual assessment and learning disabilities. Its excellent reliability, construct validity, and adoption by many school psychologists, suggests that the K-ABC possesses value in the area of cognitive assessment and in the identification/remediation of learning disabilities.
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