What is the Arizona-4? The Arizona Articulation and Phonology Scale explained

The Arizona-4, formally the Arizona Articulation and Phonology Scale, Fourth Revision, is a standardized speech assessment that measures how accurately a person produces speech sounds in single words and in sentences, and whether systematic patterns of sound errors are present. Published by WPS in 2017 and authored by Janet B. Fudala and Sheri Stegall, it covers ages 18 months through 21 years, 11 months, and each of its tests takes roughly 5 to 20 minutes to administer. Speech-language pathologists use it to identify "speech sound disorders," to describe how understandable a person's speech is, and to plan treatment. This article explains what the Arizona-4 measures, how its three tests work, how scores are interpreted, how it compares with the GFTA-3, and why a speech score says nothing about intelligence.

According to WPS, the Arizona-4 measures three related things in one assessment: speech intelligibility, articulatory impairment, and phonological impairment. "Articulation" refers to the physical production of individual speech sounds, such as saying the /r/ in "rabbit" correctly. "Phonology" refers to the sound system of a language, and "phonological error patterns" (sometimes called phonological processes) are systematic simplifications that affect whole classes of sounds, such as leaving the final consonant off every word.

The distinction matters for treatment. The American Speech-Language-Hearing Association describes speech sound disorders as any difficulty with the perception, motor production, or phonological representation of speech sounds, and notes that a single child can show both articulation errors and phonological patterns. These difficulties are common in early childhood. The National Institute on Deafness and Other Communication Disorders reports that 8 to 9 percent of young children have speech sound disorders, and roughly 5 percent of children still have noticeable speech disorders by first grade.

The Arizona-4 was standardized on a nationally representative sample of 3,192 children, adolescents, and young adults aged 1 year, 6 months to 21 years, 11 months, stratified to match U.S. Census data for gender, race and ethnicity, parental education, and geographic region. The publisher also collected a clinical validation sample of 50 individuals with diagnosed speech sound disorders to check that the test separates clinical from typically developing speech.

WPS describes the Arizona-4 as three tests in one assessment, and clinicians can use them singly or in combination.

• Word Articulation: The examinee names pictured words, repeats them after the clinician, or reads them. The clinician listens and records how the target sounds are produced on the record form. Full-color illustrations keep the task engaging for very young children.

• Sentence Articulation: The same target words are embedded in brief, simple sentences written at a first-grade reading level, which the examinee reads or repeats. Because the words match the Word Articulation items, the clinician can directly compare sound production in single words with sound production in connected speech, where errors often increase.

• Phonology: Rather than a separately administered task, the Phonology test is coded by the clinician from the examinee's productions during Word Articulation. Using the Phonology Coding Form, the clinician codes for 11 phonological error patterns to determine whether the person's errors follow systematic rules.

The Arizona-4 also includes five optional, nonstandardized supplemental tasks that add qualitative information for treatment planning, along with scoring guidance for dialectal variations. That last feature reflects a broader professional standard: ASHA cautions that standard scores should not be reported when a test's norms do not represent the person being tested, a frequent concern with multilingual and multidialectal speakers.

The primary score is the Word or Sentence Articulation Total Score. According to WPS, research links Total Scores to how often misarticulated sounds occur in everyday American speech, so the Total Score comes with Speech Intelligibility Interpretation Values that describe the real-world impact of the errors in plain language parents can understand.

Several additional scores support clinical interpretation.

• Standard scores with severity ranges: Word Articulation, Sentence Articulation, and Phonology each yield a "standard score" that compares the examinee with typically developing peers of the same age (and, at younger ages, the same gender). Severity ranges describe the level of articulatory or phonological impairment, and confidence intervals, percentile ranks, and test-age equivalents are also provided.

• Word–Sentence Articulation Critical Difference Score: This score flags clinically meaningful gaps between articulation in single words and articulation in connected speech, which helps clinicians decide what to target in therapy.

• Percentage of Occurrence: For each phonological error pattern, the clinician can compute how often the pattern appears, which helps prioritize treatment goals.

• Percentage of Speech Improvement Score: Used at retesting, this score quantifies change over time, which is useful for progress monitoring and for documenting response to therapy.

Scoring can be done by hand or through the publisher's free digital scoring and report generation on the WPS Hub platform.

The Arizona-4 is designed for speech and language professionals and carries a Level C purchasing qualification, meaning it is sold to users with advanced training in assessment. WPS lists schools, clinics, hospitals, private practices, and early intervention programs as typical settings.

In U.S. public schools, articulation measures like the Arizona-4 often appear in special education evaluations. Under the federal IDEA regulations, "speech or language impairment" is defined as a communication disorder, such as stuttering, impaired articulation, a language impairment, or a voice impairment, that adversely affects a child's educational performance. A standardized articulation score is one piece of evidence in that eligibility decision; teams also consider intelligibility in the classroom, teacher and parent input, and observation. When language comprehension or expression is the concern rather than speech sounds, evaluators typically turn to a language battery such as the one described in our article on the CELF-5.

The age range is worth noting. Because norms begin at 18 months and extend to 21 years, 11 months, the Arizona-4 can be used from toddlerhood through the end of public school eligibility, and the manual offers guidance for describing the speech of adults beyond the normed range.

The closest alternative is the Goldman-Fristoe Test of Articulation, Third Edition, covered in our guide to the GFTA-3. Both are individually administered articulation tests that sample speech sounds in single words and in sentences, and both are staples of school speech evaluations. The differences are practical.

• Publisher and lineage: The Arizona-4, published by WPS in 2017, descends from Fudala's original Arizona scale, while the GFTA-3, published by Pearson in 2015, was authored by Ronald Goldman and Macalyne Fristoe.

• Age range: According to Pearson, the GFTA-3 norms run from 2 years, 0 months to 21 years, 11 months. The Arizona-4 starts earlier, at 18 months, which can matter in early intervention.

• Phonology: The Arizona-4 builds phonological pattern coding into the same kit through its Phonology Coding Form. The GFTA-3 focuses on articulation, with sections for sounds in words, sounds in sentences, and "stimulability," which checks whether a misarticulated sound can be produced with support.

• Interpretation style: The Arizona-4's Total Score is designed to translate directly into intelligibility language, while the GFTA-3 reports standard scores on the familiar mean-100, standard-deviation-15 scale with separate norms for males and females.

In practice, many clinics own both, and the choice often comes down to the child's age, the need for built-in phonological analysis, and district convention.

It is worth being explicit about what the Arizona-4 does not measure. Articulation is a motor and phonological skill, and a low articulation score says nothing about a child's reasoning, memory, or learning potential. Plenty of children who cannot yet produce /r/ or /s/ correctly reason at or above age level, and evaluation teams treat speech and cognition as separate questions, which is why cognitive measures like the ones described in our overview of IQ tests for kids sit in a different part of an evaluation than an articulation scale.

For adults who want a rigorous picture of their cognitive abilities rather than their speech, the Reasoning and Intelligence Online Test, developed by RIOT IQ with psychometrician Dr. Russell T. Warne, measures adults 18 and older with 15 subtests across six cognitive indices (verbal reasoning, fluid reasoning, spatial ability, working memory, processing speed, and reaction time). It takes about 52 minutes and reports scores on the standard mean-100, standard-deviation-15 scale. Like any online measure, it does not replace an individually administered diagnostic evaluation, and it offers a well-normed starting point for understanding your own cognitive profile. You can take it at riotiq.com.

The Arizona-4 is normed for ages 18 months through 21 years, 11 months, with publisher guidance for describing the speech of adults beyond that range.

According to WPS, administration takes about 5 to 20 minutes per test. Word Articulation alone is often enough for a screening question, while a full evaluation may add Sentence Articulation and Phonology coding.

No. It measures speech sound production and phonological patterns, which are independent of intelligence. A child can have severely reduced intelligibility and entirely typical reasoning ability, or the reverse.

An articulation error is difficulty producing a specific sound, such as a distorted /s/. A phonological process is a systematic pattern that affects a class of sounds, such as deleting final consonants. The Arizona-4 assesses both.

Speech-language pathologists and other professionals with graduate training in assessment. WPS sells it at qualification Level C, and results are typically interpreted by an SLP as part of a broader evaluation.

Both test articulation in words and sentences. The Arizona-4 begins at 18 months, integrates phonological pattern coding, and ties its Total Score to speech intelligibility, while the GFTA-3 begins at age 2 and includes a stimulability section.

1. Western Psychological Services. (2017). (Arizona-4) Arizona Articulation and Phonology Scale, Fourth Revision. wpspublish.com

2. Pearson Assessments. (2015). Goldman-Fristoe Test of Articulation, Third Edition (GFTA-3). pearsonassessments.com

3. American Speech-Language-Hearing Association. (n.d.). Speech sound disorders: Articulation and phonology (Practice Portal). asha.org

4. U.S. Department of Education. (2017). Sec. 300.8(c)(11): Speech or language impairment (IDEA regulations). sites.ed.gov

5. National Institute on Deafness and Other Communication Disorders. (2024). Quick statistics about voice, speech, language. nidcd.nih.gov

Hero photo: A child's hand holds a bubble wand with a large soap bubble. Photo by Famartin (cropped), CC BY-SA 4.0, via Wikimedia Commons.