The Wechsler Individual Achievement Test—Third Edition (WIAT-III) is an
individually administered battery for assessing the achievement of those who are in
grades Pre-K (4 years old) through adulthood (19-11). It is norm-referenced, reliable and
valid. The same students were used to establish these norms as were those used for the
Wechsler Individual Intelligence Test-IV, allowing for accurate comparisons between
ability and achievement. Scores are computed in comparison to other children of the
same age and are reported in standard scores and percentiles. Standard Scores between 85
and 115, are in the Average range, and percentiles which rank a given student’s
performance in an imaginary line of 100 students ordered from the poorest (1st percentile)
to the best (99th percentile) performer. A percentile rank of 50% is exactly Average. The
Composite scores merge two or three related subtests. Following is a brief description of
the subtests:
Oral Language Subtests:
The Oral Language Composite Score is derived from the combined scores of these two subtests:
Listening Comprehension: The subtest has two components: Receptive Vocabulary measures the
listening vocabulary. Oral Discourse Comprehension measures the ability to make inferences and
remember details. The student listens to sentences and passages.
Oral Expression: This subtest has three components: Expressive Vocabulary measures speaking
vocabulary and word retrieval. The timed Oral Word Fluency measures efficiency of word retrieval and
flexibility. It requires the student to orally list words belonging to a category. Sentence Repetition
measures oral syntactic knowledge and short-term memory.
Reading Subtests:
The Reading Composite Score is derived from the combined scores of these four subtests.
Reading Comprehension: The student reads different types of passages and answers questions that
require identifying main idea, specific details, making inferences and defining vocabulary using context
clues. In addition, there are short sentence items with accompanying comprehension questions. Student
may choose to read silently or orally on portions of the subtest.
Word Reading: The student reads words of increasing difficulty from a word list until there are six
consecutive errors. The test measures word knowledge in isolation, and although it is untimed, the
examiner notes how many words could be decoded in 30 seconds. .
Pseudoword Decoding: The student reads nonsense syllables from a list until there are six consecutive
errors. This subtest isolates a student’s ability and skills in applying phonics and spelling rules as well
as phonological awareness.
Oral Reading Fluency: measures speed, accuracy, fluency and prosody in oral reading. The student
reads passages and orally answers comprehension questions.
Early Reading Skills (PreK-3) is not included in this composite score. It measures several areas
considered important for developing reading skills such as letter naming, phonological awareness and
word reading.
Mathematics Subtests:
The Mathematics Composite Score is derived from the combined scores of these two subtests:
Math Reasoning: The student is required to solve a series of problems with both verbal and visual
prompts that assess the ability to reason and problem solve mathematically. This test is untimed. The
student counts, identifies geometric shapes, and solves single- and multi-step word problems, including
items related to time, money and measurement. The student solves problems with whole numbers,
fractions or decimals, interprets graphs, identifies mathematical patterns, and solves problems related to
statistics and probability.
Numerical Operations: The student is required to solve written calculation problems, which increase
in difficulty and involve the basic operations of addition, subtraction, multiplication, and division. The
test is untimed.
Confidential
Math Fluency (Addition, Subtraction, Multiplication) This measures speed and fluency. One minute
is allowed to solve problems in each type of calculation.
Written Language Subtests:
The Written Language Composite Score is derived from the combined scores of these four subtests:
Alphabet Writing Fluency measures the ability to write letters of the alphabet within a 30 second time
limit. For grades (PK-3).
Sentence Composition This subtest test has two parts: sentence combining measures sentence
formulation and written syntactic ability. Sentence Building requires the student to formulate a sentence
using a target word.
Essay Compostion: measures spontaneous written composition skills within a 10 minute time limit.
Scoring includes mechanics, organization, and vocabulary.
Spelling: The student writes dictated spelling words of increasing difficulty until there are six
consecutive errors. The inclusion of homonyms requires the examinee to listen for context clues.
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Confidential
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WIAT Results:
Subtest
Standard Score
(range)
Percentile
Listening
Comprehension
Oral Expression
Reading Comprehension
Word Reading
Pseudoword Decoding
Oral Reading Fluency
*Early Reading Skills
Math Problem Solving
Numerical Operations
Math Fluency Addition
Math Fluency
Subtraction
Math Fluency
Multiplication
Alphabet Writing
Fluency
Sentence Composition
Essay Composition
Spelling
100 (85-115)
50 (-)%
%
%
%
%
%
%
%
%
%
%
Composite Score
Standard Score
%
Oral Language
Basic Reading
Reading Comp/Fluency
Total Reading
Percentile
100 (85-115)
%
%
50 (-)%
Mathematics
%
Mathematics Fluency
%
Written Expression
TOTAL COMPOSITE
%
%
%
%
%
%
*Not included in Composite Score.
Overall, earned scores in the Average range. The composite score for Mathematics
falls in the Average range. . .