How to Interpret Achievement Test Scores

When administered with intelligence assessments, achievement tests can help determine if a student has a learning disability. Achievements tests measure academic abilities, such as reading, writing, mathematics, and language. One of the most common tests used is the Wechsler Individual Achievement Test: Third Edition (WIAT-III). Subject abilities are depicted using standard scores and percentile ranks. Average scores are those that range from 85 to 115. Scores above and below the "typical" range show academic strengths and weaknesses. Percentile ranks indicate how well the person performed in comparison to same-age peers. For example, the 85th percentile shows a score that exceeds 85 percent of age-mates. When interpreting the WIAT-III, you must understand what each subtest assesses, especially the reading and math. Learning disabilities are most often found in these subjects.

Understanding the Reading Subtests of the WIAT-III

Interpret the Early Reading Skills subtest using standard scores and percentile ranks. This is the first reading subtest on the WIAT-III and can be administered to students in kindergarten through second grade. The Early Reading Skills subtest assesses basic reading readiness, such as letter-sound correspondence (i.e. “A” sounds like “aahh”), beginning and ending sounds (i.e. “bat” and “bike” both begin with the /b/ sound), phonological segments (i.e. /sh/-/ell/ is “shell”), and letter identification. Students with lower scores on this subtest have weak reading-readiness skills and should continually be exposed to reading activities, such as having an adult read to them.

Interpret the Reading Comprehension subtest using standard scores and percentile ranks. This is the second reading subtest on the WIAT-III and can be administered to students in first through twelfth grades. The Reading Comprehension subtest assesses a student’s ability to read passages and correctly answer questions regarding the reading. A student’s ability to read fluently, as well as his ability to make generalizations and inferences, can affect the comprehension score. Obviously, if a student cannot read, he will not be able to answer questions about the material. Therefore, students with lower scores on this subtest either suffer from weak reading skills in general or have a difficult time with comprehension. To strengthen this area, students should practice reading skills while periodically stopping to check for understanding of text.

Interpret the Word Reading and Pseudoword Decoding subtests using standard scores and percentile ranks. These are the third and fourth reading subtests on the WIAT-III and can be administered to students in first through twelfth grades. The Word Reading subtest assesses a student’s ability to read familiar and unfamiliar words. To be successful, individuals must have a solid understanding of letter sounds and phonics skills. The Pseudoword Decoding subtest requires students to apply phonics/sound awareness to decode nonsense words, such as “ib” or “ak.” Students who perform poorly on these subtests need to continue practicing word identification and phonological awareness.

Interpret the Oral Reading Fluency subtest using standard scores and percentile ranks. This is the fifth reading subtest on the WIAT-III and can be administered to students in the second through twelfth grades. The Oral Reading Fluency subtest assesses an individual’s ability to read passages with speed and accuracy. Mispronouncing, omitting, and/or adding words lower the score. Students who perform poorly on this subtest may have a difficult time reading. This may adversely affect all areas of academics. Therefore, students with weak fluency benefit from repeatedly reading texts.

Generalize the reading scores to the classroom. Based on a student's reading strengths and weaknesses, individualized strategies can be utilized to achieve academic success. A student who did well on Word Reading, Oral Reading Fluency and Pseudoword Decoding, but did poorly on Reading Comprehension, would benefit from extra comprehension assistance in the classroom. For example, teach the student to take notes or highlight key concepts while reading to improve understanding. On the other hand, a student who did well on Word Reading but poorly on Pseudoword Decoding is most likely able to remember sight-words but have difficulty with phonics skills. Thus, he would benefit from explicit phonics instruction, including letter-sound awareness.

Understanding the Math Subtests of the WIAT-III

Interpret the Math Problem Solving subtest using standard scores and percentile ranks. This is the first math subtest on the WIAT-III and can be administered to students in kindergarten through twelfth grade. The Math Problem Solving subtest assesses math reasoning skills, mainly the ability to solve word problems. This subtest contains graphs, charts, units of measurement, and pictures to aid in problem solving. Students who perform poorly on this subtest have weak reasoning skills. They would benefit from explicit math drills corresponding to the problems with which they had the most difficulty. For example, if a student missed every problem dealing with money, he needs to repeatedly review currency amounts.

Interpret the Numerical Operations subtest using standard scores and percentile ranks. This is the second math subtest on the WIAT-III and can be administered to students in kindergarten through twelfth grade. The Numerical Operations subtest assesses an individual’s ability to complete computations involving addition, subtraction, multiplication, and division. For older students, it also measures basic algebra and geometry skills. Students who perform poorly on this subtest need to practice and further develop basic math skills.

Interpret the Math Fluency subtests using standard scores and percentile ranks. This section is broken into three parts (addition, subtraction, and multiplication) and are the third, fourth and fifth math subtests on the WIAT-III. The addition and subtraction sections can be administered to students in first through twelfth grades, while the multiplication section is for third through twelfth grades. The Math Fluency subtests assess an individual's speed and accuracy in completing simple math problems. Students have 60 seconds to complete as many problems as possible in each section. Those who perform poorly on this subtest either have a difficult time quickly completing math tasks or their basic math skills are lacking.

Generalize the math scores to the classroom. Based on a student's math strengths and weaknesses, individualized strategies can be utilized to achieve academic success. Students who did well on Math Problem Solving but poorly on Numerical Operations need more practice with basic operations as opposed to word problems. On the other hand, those who did poorly on Math Fluency but well on Numerical Operations and Math Problem Solving may need additional time to complete math classwork.