What is the TWS-5? The Test of Written Spelling, Fifth Edition (and the TWS-6 that replaced it)
The TWS-5 is the Test of Written Spelling, Fifth Edition, a dictated-word spelling test for ages 6 to 18. It is not an IQ test, and a TWS-6 now exists.
The TWS-5 is the Test of Written Spelling, Fifth Edition, a norm-referenced spelling test published by PRO-ED in 2013 for students aged 6 through 18. It uses a "dictated-word" format, meaning a school-based examiner reads each word aloud from a stimulus card and the student writes it on an answer form, and it takes about 20 minutes to give to one student or to a whole class. The TWS-5 is not an IQ test. It measures one taught academic skill, spelling accuracy, and reports how a student's spelling compares with that of same-age peers in the norm sample. Nothing in it samples reasoning, and no score from it estimates general cognitive ability. In school evaluations it works as the achievement half of a picture whose ability half comes from a separate intelligence test. One thing to know before reading further: PRO-ED has since published the Test of Written Spelling, Sixth Edition, so the TWS-5 is now the previous edition.
How the TWS-5 was built and administered
According to PRO-ED's published description, the TWS-5 had two parallel forms, each containing 50 spelling words drawn from eight basal spelling series and graded word lists. The examiner dictated the words; the student wrote them. Because the response is written rather than spoken, the publisher allowed either individual or group administration.
The publisher reported that the TWS-5 was normed on a sample of 1,634 students from 23 U.S. states, and that item analyses found no gender or racial bias. Reliability was examined several ways, including coefficient alpha, alternate-form reliability under both immediate and delayed administration, test-retest reliability, and interscorer agreement. PRO-ED reported that all of those coefficients exceeded .90.
PRO-ED described three intended uses for TWS-5 results: identifying students whose spelling falls well below their peers and who may need intervention, documenting progress after intervention, and serving as an outcome measure in spelling research. The complete kit contained an examiner's manual, 50 answer and record forms, and a laminated card carrying the stimulus words. PRO-ED listed the test at its Level B qualification tier, which limits purchase to buyers who have registered professional credentials with the publisher.
The TWS-5 has been replaced by the TWS-6
PRO-ED now lists the Test of Written Spelling, Sixth Edition, copyright 2026, as the current product, and the TWS-5 complete kit no longer appears in the catalog. The only TWS-5 item PRO-ED still sells is the pack of answer and record forms, filed under the heading "reorderable forms from the previous edition."
The sixth edition keeps the design that made the TWS recognizable. PRO-ED describes it as using the same dictated-word format, with two forms (Form A and Form B) of 50 words each, again drawn from eight basal spelling series and graded word lists, and again taking 20 minutes to administer individually or in a group. The stated age range is now given precisely as 6-0 through 18-11, and the author line has grown to Donald D. Hammill, Louisa C. Moats, Melissa E. Morey, and Stephen C. Larsen.
Two changes matter for anyone comparing an old report with a new one.
• New norms. PRO-ED reports that the TWS-6 standardization used an all-new sample of 1,606 students drawn from 421 different zip codes. A standard score of 95 on the TWS-5 and the same score on the TWS-6 are referenced to different groups of children tested more than a decade apart, so the two numbers are not interchangeable.
• Scoring moved online. The publisher states that TWS-6 scoring is available only through the TWS-6 Online Administration, Scoring, and Report System, which is bundled with the complete kit and with each replacement pack of student response forms. That system converts raw scores into age and grade equivalents, percentile ranks, standard scores, and confidence intervals, and PRO-ED says dropping the printed normative tables ensures accurate calculation.
If you are commissioning a new evaluation, ask which edition will be used; a report written before 2026 will be the TWS-5.
Why a spelling test is not an intelligence test
Spelling is learned. A student's TWS score reflects instruction received, print exposure, language background, and the specific orthography of English, on top of whatever cognitive machinery supports word learning. An intelligence test samples reasoning across several domains chosen to be less dependent on any single curriculum. The two families of instruments correlate in most samples, and they still answer different questions.
That distinction is why achievement batteries such as the WIAT and the achievement side of the Woodcock-Johnson are sold separately from the cognitive batteries that often accompany them. A narrow instrument like the TWS occupies an even smaller slice of that space, covering one skill within written language.
Spelling weakness can sit alongside strong general ability, and it often does. In a study published in PLOS ONE, Belgian researchers compared 100 higher education students with dyslexia to 100 matched peers and found that the students with dyslexia showed lower spelling proficiency while judging their own confidence just as accurately as the control group. These were university students, a useful reminder that a low spelling score is a statement about spelling.
The skill is still worth measuring on its own terms. Louisa Moats, a co-author of both the TWS-5 and the TWS-6, has written in American Educator that learning to spell and learning to read rely on much of the same underlying knowledge, particularly the relationships between letters and sounds, so spelling instruction can be designed to improve reading as well. She also cites research finding that spell checkers catch roughly 30 to 80 percent of misspellings, and identified the intended word for students with learning disabilities only 53 percent of the time.
Where a spelling score fits in a school evaluation
Under the federal regulations implementing the Individuals with Disabilities Education Act, a team may determine that a child has a specific learning disability if the child does not achieve adequately for their age or grade-level standards in one or more of eight areas, one of which is written expression. The regulation then offers two routes: the child's response to scientific, research-based intervention, or a documented pattern of strengths and weaknesses in performance, achievement, or both, measured relative to age, grade-level standards, or intellectual development.
That second route is where cognitive testing enters, and it is why a spelling measure and an IQ test so often appear in the same file. The regulation also requires the team to establish that underachievement is not primarily the result of lack of appropriate instruction, supported by data showing the child received appropriate instruction from qualified personnel and by repeated assessments of achievement reported to parents.
A TWS score contributes one data point to that process. It does not identify a disability, and it does not diagnose dyslexia. Those determinations belong to qualified evaluation teams working from multiple sources of evidence, which is also the answer to the related question of whether dyslexia affects IQ test scores.
Reading a TWS score without over-reading it
PRO-ED reports that both editions yield percentiles, standard scores, and age and grade equivalents. Those score types carry very different amounts of information.
• Percentile rank: the share of the norm sample that the student's raw score equals or exceeds. A percentile of 18 means about 82 percent of same-age peers in the norm sample spelled more words correctly.
• Standard score: the raw score placed on a common scale referenced to the norm sample, which makes it comparable with other normed instruments in the same evaluation. Check the manual for the scale used before setting it beside an IQ score.
• Age and grade equivalents: the age or grade at which the student's raw score would be typical. These are the least stable scores on any achievement test, because a small difference in raw score can move a grade equivalent by a year, and a fourth grader who earns a "second grade" equivalent has not been shown to spell the way a typical second grader spells.
• Confidence interval: the band around the standard score that reflects measurement error. The TWS-6 online system reports upper and lower bounds, and the band is the finding.
One 20-minute dictation on one morning is a thin slice of a student's written language. A score that surprises everyone who knows the child is a reason to look further.
Getting a separate read on reasoning
Because a spelling test deliberately measures a taught skill, it cannot tell you whether a struggling speller is behind relative to their own reasoning ability. That question needs a cognitive measure, which for school-age children means an individually administered battery given by a school psychologist.
For adults who want a well-constructed picture of their own reasoning, the Reasoning and Intelligence Online Test is one option. Developed by RIOT IQ with psychometrician Dr. Russell T. Warne, it is designed for adults 18 and over, runs 15 subtests across six cognitive indices covering verbal reasoning, fluid reasoning, spatial ability, working memory, processing speed, and reaction time, takes about 52 minutes, and reports scores on the familiar scale with a mean of 100 and a "standard deviation," a measure of how spread out scores are, of 15 points. It does not replace an individually administered diagnostic evaluation. You can take the RIOT IQ test if you want a reasoning score to sit alongside academic results.
Frequently asked questions
Is the TWS-5 an IQ test?
No. The TWS-5 is an achievement test that measures spelling accuracy using dictated words. It produces no estimate of general cognitive ability, and its score should not be read as one.
Is the TWS-5 still the current edition?
No. PRO-ED now publishes the Test of Written Spelling, Sixth Edition, copyright 2026. The TWS-5 complete kit has been withdrawn from the catalog, and the remaining TWS-5 answer forms are sold under a "previous edition" label.
What ages does the Test of Written Spelling cover?
PRO-ED gave the TWS-5 range as 6 through 18 years, and lists the TWS-6 range as 6-0 through 18-11.
How long does the test take?
The publisher reports 20 minutes for both editions, and both may be given individually or to a group.
Can a spelling test diagnose dyslexia?
No. A spelling score is one piece of evidence within a wider evaluation. Identification of a specific learning disability is made by a qualified team using multiple measures, instructional history, and the criteria set in federal and state regulation.
Can I compare a TWS-5 score directly with a TWS-6 score?
Not reliably. The sixth edition was standardized on a new sample of 1,606 students, so identical standard scores refer to different comparison groups tested years apart.
References
1. PRO-ED. (2026). TWS-6: Test of Written Spelling–Sixth Edition, Complete Kit [Product page]. proedinc.com
2. PRO-ED. (2013). Reorderable forms from the previous edition: TWS-5 Answer and Record Forms (50) [Product page]. proedinc.com
3. PRO-ED. (2013). TWS-5: Test of Written Spelling–Fifth Edition: Complete Kit [Archived product page]. Internet Archive. web.archive.org
4. Moats, L. C. (2005). How spelling supports reading: And why it is more regular and predictable than you may think. American Educator, 29(4), 12–22, 42–43. aft.org
5. U.S. Department of Education. (2026). 34 CFR § 300.309: Determining the existence of a specific learning disability. Electronic Code of Federal Regulations. ecfr.gov
6. Callens, M., Tops, W., Stevens, M., & Brysbaert, M. (2014). Metacognition for spelling in higher education students with dyslexia: Is there evidence for the dual burden hypothesis? PLOS ONE, 9(9), e106550. journals.plos.org
Hero image: “Hand-writing-exam-classroom.jpg” by Alison wood, licensed CC BY 3.0, via Wikimedia Commons (https://commons.wikimedia.org/wiki/File%3AHand-writing-exam-classroom.jpg).
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