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Running Head: NON-VERBAL ASSESSMENT OF INTELLIGENCE
Non-Verbal Assessment of Intelligence:
A Review of Information Learned Through the Administration of Three Non-Verbal Cognitive
Assessments
Sarah Pemble
EdPsy 533
Washington State University
April 13, 2009
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Abstract
Three non-verbal cognitive assessments were administered to establish familiarity with nonverbal cognitive assessment. The Test of Non-verbal Intelligence 3rd Edition (TONI), Kaufman
Assessment Battery for Children 2nd Edition (KABC-II), and the Differential Ability Scales
(DAS) administered. One student was administered all three tests at different times. At the time
of testing, the student was 17 years and 6 months old. The student is male and he identifies
himself as African American. He was given a $25 gift card for participating. Data analysis
indicates invalid test results due to administration error.
The purpose of this assignment is to communicate the valuable information that was learned
though the administration of the KABC-II, TONI-3, and the DAS. This will specifically be
addressed in sections detailing (a) an introduction to non-verbal assessment, (b) psychometrics,
(c) administration, and (d) teacher and student value.
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Non-Verbal Assessment of Intelligence
Non-verbal assessment of intelligence measures a person’s capacity to act purposefully,
to think rationally, and to deal effectively with the environment. Non-verbal assessment does not
refer to a person’s non –verbal intelligence, rather it refers to the type of items administered on a
test. Intelligence tests with verbal and non-verbal content measures the same domains of general
ability as tests that are solely non-verbal. Generally, non-verbal assessments measures a student’s
ability to recognize underlying rules and relationship, ability to remember details, ability to see
and reproduce conceptual patterns, reasoning skills, and complete sequences. Non-verbal tests
deemphasize the role of reading, and minimize language (but is not necessarily eliminated).
Language –free tests (to be distinguished from non-verbal tests) are administered in pantomime
or gesture and requires no language capacity. Aside from the KABC-II, TONI-3, and the DAS
other non-verbal intelligence tests include the Unit, Leiter International Performance Scales,
Comprehensive Test of Non-verbal Intelligence (CTON), and Wechsler Intelligence Scale for
Children (WISC) perceptual organization subtests.
Non-verbal assessments may be appropriate measures if the person is speech or hearing
disabled, an English Language Learner (ELL), illiterate, or when teachers suspect a non-verbal
learning disorder. Other tests or activities that are loaded with spoken or written language tasks
could be helpful in estimating the potential of students who are nonverbal, illiterate, or nonEnglish speaking.
The use of non-verbal cognitive testing has two major criticisms (known to this author).
Verbal and communication skills are central to overall intelligence, and non-verbal intelligence
testing inadequately asses these qualities. Secondly, non-verbal cognitive assessment
inadequately asses the student’s use of verbal mediation to problem solve.
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The main three theories of non-verbal intelligence include Spearman’s “G” and “S” two
factor theory, Cattell’s fluid and crystallized measures, and Thurstone’s primary mental abilities.
Spearmans’s “G” and “S” two factor theory was developed in 1927. The “G” factor refers to a
general intelligence factor common to all tests and a specific factor that is distinctive in each test.
Therefore, the general ability factor will determine how well each student does on any particular
assessment. In addition to the general “G” factor, the “S” or specific factor is unique to each test
that will also influence the overall assessment outcomes. These two factors equate the
intelligence.
Thurstone’s primary mental abilities was developed in 1941 and examines verbal abilities
such as word relations/vocabulary, number abilities including accuracy and speed, spatial
abilities, word fluency through the use of rapid recall of words, memory abilities, and reasoning
abilities. These domains comprise intellectual behavior. These domains have also been identified
as real world tasks.
Lastly, Raymond Cattells’ fluid verses crystallized intelligence was developed in 1963.
Fluid intelligence represents a person’s ability to problem solve, to make meaning out of chaos,
to draw inferences, and the ability to understand complex and dynamic relationships. Fluid
intelligence does not rely on acquired knowledge. Crystallized intelligence is the ability to
integrate prior knowledge, experience and skill into a novel situation. It is not necessarily
equivalent to knowledge; however the long term memory is an important constituent.
DAS II
The Differential Ability Scales was originally developed from the British Ability Scales
in 1990. The DAS II was released in 2007. The DAS is a very complicated test to administer
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and score. There are 20 subtests in total; 17 cognitive tests and 3 achievement measures yields an
overall cognitive and achievement scores. Research indicates that the DAS is valid for children
two years and six month old through seventeen years and eleven months old. The General
Conceptual Ability (GCA) is the general ability of an individual to perform complex mental
processing that involves conceptualization and the transformation of information. The DAS also
provides cluster or composite scores. The Figure 1 bellow diagrams the subtests and the general
process to achieve the GCA.
Figure 1
Psychometrics
Reliability. The DAS was standardize between 1986 and 1989. A total of 3, 475 students
participated. The sample was stratified by age, sex, geographic location, special education,
enrollment, across race-ethnicity, and parent education levels. The 1988 census was used to
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create a representing sample. Interestingly however, the demographics used in this study no
longer accurately represent the 2009 US census.
In reference to internal reliability, a coefficient alpha of .89 and .90 for Preschool Nonverbal Ability and School-age Non-verbal Reasoning Ability was established, and coefficient
alpha of .92 for the Spatial Ability Scores. Some subtests at some ages do not have sufficient
reliability for individual interpretation, most notably the Recognition of Pictures subtest for out
of level testing (7 and older) and the alternate (untimed) Pattern Construction subtest (12 and
older).
In reference to Test-retest reliability, there were significant practice-effects in the Nonverbal Subtest. Students were retaining and learning information from the test, and their scores
improved. Measures of the Verbal Ability were more stable with fewer practice effects.
Validity. In reference to construct validity, the DAS Verbal, Nonverbal, and GCA scores
were generally lower than the WPPSI-R Verbal, Performance, and Full Scales. In addition, the
DAS Non-verbal Reasoning Score correlated higher with the WISC-R Verbal, than with the
Performance. The DAS Spatial cluster correlated highest with the WISC-R.
Administration
The DAS is a complicated and integrative system of subtests and scoring procedures. The
DAS requires much preparation prior to professional administration. The experienced tester will
likely need the manual during administration for scoring purposes. The scoring is somewhat
subjective on some of the subtests, and the accuracy of the results will largely depend on
administrator’s competencies. Like many other tests, there is a basal and discontinue rule.
However, unlike other tests, there is no uniform start or end point. An administrator can test out
of age. For example, the administrator believes that the starting items are too simple, he or she
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can move the student to the next starting point (and the reverse is true as well). All subtest
include teaching items. The test took much longer than anticipated and this is likely due to the
fact that this tester was simply unfamiliar with the DAS administration. Item by item
administration and scoring was the most time consuming and relied more on professional
judgment.
Value
The DAS presents with several strengths. The DAS separates verbal ability, non-verbal
reasoning, and spatial ability into cluster scores for a meaningful interpretation for the student
and teachers. Out of level testing may be attractive when testing children with disabilities. The
diagnostic subtests prove useful when exploring a student’s strengths and challenges. The
accompanying manual is comprehensive and complete, proven to be a necessity for proper
administration of the DAS. The manual is especially useful when planning the appropriate
assessment of a student. The DAS is very elaborate, and it yields a wealth of information. The
DAS has been proven to be the most reliable non-verbal assessment. Although the DAS is
complicated to administer, my student seemed to enjoy this test more than any other.
Aside from the strengths, the DAS has several apparent weaknesses. It presents as
confusing for the new school psychologist. Much practice is needed to be competent in
administering and scoring this assessment. If timed procedures are not used, the reliability
decreases. The start and stop points are confusing, and rely on administrator judgment.
I incorrectly administered the DAS. I missed an entire sub test, which proved to be a
good learning experience. During administration, I relied heavility on the manual, which proved
to be time consuming and I imagine as I gain familiarity with the DAS the assessment process
with go much smoother.
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KABC-II
The KABC-II was published in 2004. It’s dual theoretical foundation is based on the
Luria neurological model and, the Cattell- Horn-Carroll (CHC) model. The CHC model is
designed for students from an industrialized, mainstream culture and language background and
thus relies on a student’s crystallized ability. When testing from the CHC model, the KABC-II
includes all the scales in the Luria model, but they are scored differently. The Knowledge/Gc
Scale is exclusive to the CHC model. The global scores produces the Fluid-Crystallized Index
(FCI).
The Luria model is designed for the student where his/her crystallized ability is not the
best indicator of cognitive ability and therefore excludes verbal components. For example, use
the Luria model when the student has a bilingual background, whose cultural background may
affect knowledge or verbal development, or when there is a suspected language disorder or
hearing impairment. When working from the Luria model, the KABC-II measures learning,
sequential, and simultaneous processing and planning abilities and, deemphasizes acquired
knowledge. The Luria model yields a global score called the Mental Processing Index (MPI).
The KABC-II is designed for students ages three to eighteen years old. There are 18
subtest, and about 12 core subtest (depends on model selected and age of student). The nonverbal subtests include face recognition, story completion, triangles, pattern reasoning, hand
movements, and conceptual thinking.
Psychometrics
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The KABC-II standardization process occurred between September 2001 and January
2003. A total of 3,025 students between the ages of two and eighteen participated.
Approximately 125-200 students are represented for every age group. Testing occurred at 127
sites, and in 39 states. The participants in the study matched the 2001 US census pertaining to
gender, ethnic group, parental education, geographic region, special-education and gifted
placement.
Reliability. The KABC-II demonstrates good reliability. Subtest reliability coefficients
are .80 to .90. Global/individual scales are .81 to .97 but, coefficients for the non-verbal are the
lowest at .90. The stability of the subtests coefficients are .50 to .92. Younger girls scored better
then boys on all scales except knowledge. Parent education proved to be an important predictor
for all pre-school and knowledge on scales for school age.
Validity. The KABC-II demonstrates strong construct validity on the global scales. The
KABC-II correlated with the Wechsler with a full scale of 97.3. The full IQ correlation with the
WISC and FCI/MPA is .89 and .88. Subscale and index scores correlation are present with IQ
scores on the WISC-III, WISC-IV, WPPSI-III, and KAIT.
Administration
Administration of the KABC-II is much simpler than the DAS. The KABC-II is
individually administered. The time it takes to administer the test depends on the model
administered. The Luria core battery takes between 25-55 minutes, and the CHC core battery
takes about 35-70 minutes to administer. The scoring method will depend on the model chosen,
either the Luria Model or the CHC Model. The non-verbal subtests are administered in
pantomime and responded to motorically.
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Value
The KABC-II identifies a student’s cognitive strengths and weaknesses, and provides
useful information to better understand how he/she receives and processes information. Out of
level administration is optional and requires administrator judgment. Bi-lingual
(Spanish/English) non-verbal scales includes an easel in Spanish translations for teaching and
score interpretation. Administrator can record observations about test-taking behaviors for
example, fails to sustain attention, reluctant to respond when uncertain, unusually focused,
worries about time limit, and verbalizes story ideas. The CHC model is recommended for gifted
students, a definite bonus. The KABC-II boasts of exceptional fairness. The subtests are
designed to be culturally sensitive and this is achieved through minimal verbal instruction and
responses. The KABC-II claims to contain little cultural content. The KABC-II has a dual
theoretical model designed to provide the school psychologist with options.
TONI-3
Value
The teacher and student need to understand test results in a way that makes sense and
directly applies to the student’s ability to learn. Simply restating test scores will most likely be a
waste of time as the teacher and certainly the student will not be able to translate that information
into the classroom. For example, Jonny’s raw score of 22 was converted to a quotient of 98 and
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to a percentile rank of 45 which indicates that he is performing in the average range when
compared with other students who took the test.
The following image is an item from the TONI-3. This is item number 45 from Form A
and it is the most complex item. A student must see the patterns formed by the shapes organized
in to groups, rotated, and then choose an answer that completes the pattern. In this example, the
student has to understand that the shapes form a pattern throughout the two-by-two matrix.
The same basic intellectual activity required to solve this problem can be generalized to
many academic tasks, regardless of content. For example, understanding a written paragraph
requires a student to understand how various pieces of information are connected. Building
phonemic awareness often involves seeing patterns in a sequence of letters. Geometry requires
the student to recognize the patterns and relationships among concepts and numbers.
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Because a nonverbal tests measures basic and novel ways of thinking, it helps teachers
and school psychologist have a better appreciation of their ability and academic potential.
Additionally, because the test items do not require language, the assessment’s cultural loading is
minimal (or at least significantly reduced) when compared to the verbal counterpart. Other test or
activities that are loaded with spoken or written language tasks could be helpful in estimating the
potential of students who are nonverbal, illiterate, or non-English speaking. However, test
administrators should be cautious and consider a language deviance rather than intellectual
deviance when a student’s profile is characterized by normal or above average on non-verbal
measures combined with sub-average performance on language-loaded measures.