What is the WMLS-III? The Woodcock-Muñoz Language Survey explained
The WMLS-III (Woodcock-Muñoz Language Survey III) measures English and Spanish academic language proficiency for ages 3 to 22. Learn its scores and uses. (153 chars)
Dr. Russell T. WarneChief Scientist
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The WMLS-III, or Woodcock-Muñoz Language Survey, Third Edition, is an individually administered, norm-referenced test of academic language proficiency in English, Spanish, or both. Published in 2017 and distributed by Riverside Insights, it measures listening, speaking, reading, and writing for individuals from age 3 years, 0 months through 22 years, 11 months. Schools use it to identify English learners, determine eligibility for bilingual and ESL services, establish language dominance, and decide which language should be used for cognitive or academic testing. This article explains what the WMLS-III measures, how its scores work, and where it fits in the wider Woodcock-Johnson family of assessments.
What the WMLS-III measures
According to the publisher's assessment service bulletin, the WMLS-III offers "an extensive sampling of academic language proficiency, in English and/or Spanish, in the domains of listening, speaking, reading, and writing." The word "academic" matters here. The survey deliberately targets the formal language of classrooms and textbooks rather than everyday conversational fluency, because a student can chat comfortably in a language long before they can learn algebra or write an essay in it.
The test kit contains three parallel forms of equivalent difficulty: two in English and one in Spanish. Because the forms are parallel, an examiner can directly compare a student's performance across the two languages, or retest later in the same language to measure growth. Each form contains eight tests, two for each of the four domains:
• Listening: "Analogies" and "Oral Comprehension" measure how well the examinee understands spoken language, from word relationships to missing words in spoken passages.
• Speaking: "Picture Vocabulary" and "Oral Language Expression" sample expressive skills, from naming pictured objects to producing connected spoken language.
• Reading: "Letter-Word Identification" and "Passage Comprehension" cover decoding printed words and understanding written text.
• Writing: "Dictation" and "Written Language Expression" assess spelling and the ability to compose written sentences.
Examiners rarely give every test. The battery uses a selective testing model, so a school can administer only the oral language tests for a quick screening or the full set for a comprehensive evaluation. The tests combine into five oral language clusters and five literacy clusters, plus cross-domain composites of overall language ability. The publisher's brochure lists about one hour for a full battery, and the distributor WPS lists a typical administration time of 25 to 55 minutes, depending on how many tests are given.
CALP and the six language proficiency levels
The signature output of the Woodcock-Muñoz series is its measure of "cognitive academic language proficiency," usually shortened to CALP. Riverside Insights states that the WMLS-III measures CALP across all four domains. The concept comes from the linguist Jim Cummins, who distinguished between language learned naturally for informal settings and language that develops in formal educational environments. The WMLS-III targets the second kind, the discrete and academic language skills that predict whether a student can handle grade-level instruction.
In the third edition, this information is reported through six "language proficiency levels." From lowest to highest, they are Initial Development, Early Development, Continuing Development, Emerging Proficiency, Proficient, and Advanced Proficient. Each level is tied to the examinee's distance from average same-age peers on the test's underlying measurement scale, and each carries a practical prediction. The publisher's bulletin explains that an examinee at the Proficient level is expected to succeed on 74 to 97 percent of academic language tasks that typical peers perform with 90 percent success, while an examinee at the Early Development level would manage only 3 to 17 percent of those same tasks. That framing tells a teacher something a bare score cannot: how much linguistic support a student is likely to need in an English-only classroom.
Alongside the proficiency levels, the WMLS-III produces familiar norm-referenced scores, including standard scores, percentile ranks, and age and grade equivalents, as well as a "relative proficiency index" that predicts task success against age or grade peers.
The comparative language index and language dominance
A distinctive feature for bilingual evaluation is the "comparative language index," or CLI. Riverside Insights describes the CLI as a tool to identify language dominance and guide academic planning. Because the English and Spanish forms are parallel, the CLI can express a student's proficiency in one language relative to the other on the same yardstick. That comparison answers a question that comes up constantly in schools: is this student stronger in English or in Spanish, and by how much?
Dominance information has real consequences. It shapes which language a bilingual program uses for initial literacy instruction, and it determines the language in which any further cognitive or academic testing should be conducted. Testing a Spanish-dominant child in English measures their English, whatever the test claims to measure, a point that applies to vocabulary measures such as the one covered in our article on the Peabody Picture Vocabulary Test.
How schools use the WMLS-III
The publisher's materials describe several core uses, most of them centered on English learners and bilingual students.
• English learner identification and program eligibility: The brochure lists determining eligibility for bilingual and ESL services among the survey's primary purposes, along with judging readiness for English-only instruction. Districts also use proficiency results to monitor progress and inform reclassification decisions as students approach exit criteria.
• Language of assessment decisions: Before a psychologist evaluates a bilingual child for a disability, the WMLS-III can establish which language will yield a fair picture of the child's abilities. Federal special education law expects evaluations in the child's native language where feasible, and the bulletin notes that English learners should be assessed both in their native language and in English.
• Bilingual special education evaluation: Comparing parallel English and Spanish results helps evaluators distinguish a language difference (typical development in a second language) from a language disorder that appears in both languages.
• Reading and writing concerns: The publisher also lists assessing for dyslexia and dysgraphia and monitoring growth or change in either language.
The test requires a trained examiner, and results are scored through Riverside's web-based scoring platform, which generates teacher and parent reports in English or Spanish.
The Woodcock-Johnson family connection
The WMLS-III is part of the Woodcock-Johnson family of test batteries and, according to the publisher's bulletin, is co-normed with the Woodcock-Johnson IV. Co-norming means the instruments share a common norming framework, so scores can be compared across batteries with less statistical noise. If you want the fuller picture of that flagship battery, see our guide to the Woodcock-Johnson test.
In practice, the WMLS-III often functions as the front door to a larger evaluation. Riverside's own sample scenario has an examiner using the survey to establish language dominance, then choosing between the Woodcock-Johnson IV in English and the Batería IV Woodcock-Muñoz, which the publisher describes as the parallel Spanish version of the WJ IV, for the follow-up cognitive and achievement testing. Used together, the batteries let an evaluator compare a student's skills in Spanish and English directly.
Language proficiency and IQ testing
The WMLS-III measures language proficiency rather than intelligence, yet the two intersect in an important way. Most cognitive tests lean on language somewhere, and verbal subtests lean on it heavily. A low score on a verbal reasoning task can reflect limited English exposure rather than limited reasoning ability, which is exactly the confusion the WMLS-III exists to prevent. Our article on what verbal reasoning measures explains why vocabulary and verbal knowledge are so central to cognitive assessment.
This is worth stating plainly for online testing too. The Reasoning and Intelligence Online Test, developed by RIOT IQ with psychometrician Dr. Russell T. Warne, was normed on US-born native English speakers. For adults 18 and older who are proficient in English, it offers 15 subtests across six cognitive indices (verbal reasoning, fluid reasoning, spatial ability, working memory, processing speed, and reaction time) in about 52 minutes, with scores on the familiar mean-100, standard-deviation-15 scale. For an examinee still developing English proficiency, scores on the verbal portions of any English-language test should be interpreted cautiously, and no online test replaces an individually administered bilingual evaluation when eligibility decisions are at stake.
FAQ
What ages does the WMLS-III cover?
The publisher states it is appropriate for ages 3 years, 0 months through 22 years, 11 months, which spans preschool through college.
Is the WMLS-III an IQ test?
No. It measures academic language proficiency in English and Spanish. It is co-normed with the Woodcock-Johnson IV, a separate battery that measures cognitive abilities and achievement.
What are CALP levels on the WMLS-III?
The third edition reports six language proficiency levels, from Initial Development to Advanced Proficient, that describe an examinee's command of cognitive academic language, the formal language of school.
How long does the WMLS-III take?
It depends on which tests are administered. The distributor lists 25 to 55 minutes for typical administrations, and the publisher's brochure lists about one hour for a full battery.
Can the WMLS-III tell whether a student is stronger in English or Spanish?
Yes. Its parallel English and Spanish forms and the comparative language index are designed to establish language dominance and to compare proficiency across the two languages.
Who administers the WMLS-III?
Trained examiners such as school psychologists, speech-language pathologists, bilingual educators, and ESL specialists. It is a qualification-restricted instrument, so it is purchased and given by professionals rather than parents.
Closing thoughts
The WMLS-III answers a narrow question with unusual care: how well can this person use English or Spanish for academic work? Getting that answer right protects students from two opposite errors, denying language support to a child who needs it and mistaking a language difference for a cognitive deficit. If you are an English-proficient adult curious about your own cognitive abilities, you can take the RIOT IQ test at riotiq.com, and if a formal eligibility or diagnostic question is on the table, an individually administered evaluation by a qualified professional remains the right path.
References
1. Riverside Insights. (2026). Woodcock-Muñoz Language Survey III (WMLS III): Spanish and English language proficiency assessment.. riversideinsights.com
2. Duffy, K. R., Stephens-Pisecco, T. L., & Schultz, E. K. (2018). WMLS III: Comprehensive assessment, intervention, and application (WMLS III Assessment Service Bulletin No. 1). Houghton Mifflin Harcourt. 7083436.fs1.hubspotusercontent-na1.net
3. Riverside Insights. (n.d.). Woodcock-Muñoz Language Survey III (WMLS III) brochure: Assess academic language proficiency in English and Spanish.. riversideinsights.com
4. Western Psychological Services. (n.d.). (WMLS III) Woodcock-Muñoz Language Survey.. wpspublish.com
Internal links used in body: - Peabody Picture Vocabulary Test → https://www.riotiq.com/articles/specific-iq-tests-and-formats/what-is-the-peabody-picture-vocabulary-test (anchor: "our article on the Peabody Picture Vocabulary Test") - Woodcock-Johnson test → https://www.riotiq.com/articles/specific-iq-tests-and-formats/what-is-the-woodcock-johnson-test (anchor: "our guide to the Woodcock-Johnson test") - Verbal reasoning → https://www.riotiq.com/articles/general-iq-and-intelligence/what-is-verbal-reasoning (anchor: "what verbal reasoning measures") - Closing CTA → https://www.riotiq.com/ (anchor: "take the RIOT IQ test at riotiq.com")
Photo by LinguistAtLarge, via Wikimedia Commons (CC BY-SA 3.0)
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