What is the KLPA-3? The Khan-Lewis Phonological Analysis explained
The KLPA-3 analyzes phonological processes in a child's speech from GFTA-3 responses, for ages 2 to 21. Learn what it measures and why it is not an IQ test.
Dr. Russell T. WarneChief Scientist
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The KLPA-3, short for the Khan-Lewis Phonological Analysis, Third Edition, is a norm-referenced analysis of the "phonological processes" a child uses in speech, meaning the systematic sound changes that simplify words, such as leaving off a final consonant or turning "k" into "t." It is published by Pearson, covers ages 2 years 0 months through 21 years 11 months, and is scored by a speech-language pathologist from a child's responses on the Goldman-Fristoe Test of Articulation, Third Edition (GFTA-3). The KLPA-3 is not an IQ test. Its score says nothing about reasoning, memory, or general intelligence. This article explains what the analysis looks for, how it depends on the GFTA-3, how it is scored, and how it differs from a cognitive ability test.
What the KLPA-3 measures
The American Speech-Language-Hearing Association (ASHA) defines phonological patterns as "systematic sound changes or simplifications that affect a class of sounds (e.g., fricatives), sound combinations (e.g., consonant clusters), or syllable structures." A two-year-old who says "wabbit" is using a process called gliding; a child who says "nana" for "banana" is reducing syllables. ASHA notes that children "often demonstrate 'typical' errors and phonological patterns during this learning period." The clinical question is whether the patterns persist past the age at which most children have dropped them.
According to Pearson, the KLPA-3 "works with Goldman-Fristoe 3 to help determine if use of phonological processes are contributing to an individual's speech sound disorder." The authors are Linda M. L. Khan and Nancy P. Lewis, both speech-language pathologists, and the current edition was published in 2015.
Pearson's sample GFTA-3/KLPA-3 score report describes the analysis as identifying the "frequency of usage of twelve Core Phonological Processes grouped into four types of processes (manner, place, reduction and voicing Processes), twelve Supplemental, and other processes." The 12 core processes are:
• Manner processes: deaffrication, gliding of liquids, stopping of fricatives and affricates, stridency deletion, and vocalization. These change how a sound is made, such as replacing a hissing "s" with a stopped "t."
• Place processes: palatal fronting and velar fronting. These move a sound forward in the mouth, so "cat" becomes "tat."
• Reduction processes: cluster simplification, deletion of final consonant, and syllable reduction. These drop parts of a word, so "spoon" becomes "poon" or "dog" becomes "do."
• Voicing processes: final devoicing and initial voicing. These switch a sound between its voiced and voiceless form, so "pig" sounds like "pick."
Only these 12 core processes feed the standard score. The 12 supplemental processes and a set of eight vowel processes are reported as counts and percentages for treatment planning without being scored against norms.
How the KLPA-3 relates to the GFTA-3
The KLPA-3 has no picture cards or test items of its own. Pearson's report states that it "requires the administration of the 60 target words of the Sounds-in-Words test" from the GFTA-3, after which "the target words are analyzed for sound changes and the sound changes are classified by phonological process(es)." The clinician gives the articulation test first, records every consonant error, and then reanalyzes those errors to see which phonological processes explain them. Our guide to the GFTA-3 covers the articulation test itself, including its Sounds-in-Sentences, stimulability, and intelligibility measures, none of which are used by the KLPA-3.
The GFTA-3 counts individual sound errors. The KLPA-3 asks whether those errors follow a rule. A child who mispronounces "s," "z," "f," and "sh" in the same way is likely using a single stopping process rather than four separate articulation problems, which changes the therapy target. Pearson describes the KLPA-3's purpose as helping clinicians "make informed therapy decisions" and record remediation goals for common processes.
Pearson lists three ways to obtain scores: a KLPA-3 report purchased on its Q-interactive iPad platform after a GFTA-3 administration, a combined report on Q-global after the clinician enters GFTA-3 item scores, or hand scoring with the KLPA-3 Analysis Form and Sound Change Booklet. The publisher's comparison flyer gives an average of 10 to 30 minutes for hand scoring and "3 seconds" for the digital options. The flyer also notes that the KLPA-2 identified processes by examining the whole word, while the KLPA-3 examines each phoneme.
Scores and the norm sample
Pearson's report explains that "the total number of phonological processes included in the 12 Core Processes are converted into a series of scores (mean of 100 and a standard deviation of 15) based on age and gender-based norms." The "standard deviation" is a measure of how spread out scores are, so a score of 85 sits one standard deviation below the average of same-age, same-sex peers. Because the raw score counts errors, a higher standard score means fewer phonological processes and more mature speech. The report also provides a 95 percent confidence interval, a percentile rank, an age equivalent, and a percent-of-occurrence figure for each core process.
The publisher's comparison flyer reports that the KLPA-3 was standardized on 1,500 examinees at 198 sites in the United States, with the sample matched to the 2013 U.S. Census American Community Survey. About 13.2 percent of the sample was bilingual with English as the primary language, and it included children in special education as well as those identified as gifted. Our article on what a norm group is explains why this comparison group matters.
The same flyer reports internal consistency coefficients of .81 to .99, test-retest stability of .94, and inter-scorer agreement for the core processes of .98 to 1.0. Scores correlated .73 with the KLPA-2 and averaged about 4.5 standard score points lower. Pearson also reports "sensitivity" and "specificity," the proportions of children with and without a diagnosed speech sound disorder that a cut score classifies correctly. At a cut of one standard deviation below the mean, the flyer lists sensitivity of .93 and specificity of .83. The score is meant to inform a clinician's judgment rather than replace it.
Why phonological processes are worth measuring
Most children outgrow phonological processes on a fairly predictable schedule. A 2020 review in the American Journal of Speech-Language Pathology by Kathryn Crowe and Sharynne McLeod pooled 15 studies of 18,907 children acquiring English in the United States and found that most consonants were acquired by age 5. Sounds such as "b," "m," and "w" were acquired by age 2, "k," "g," and "f" by age 3, "s," "l," and "sh" by age 4, "r" by age 5, and the voiceless "th" by age 6. The KLPA-3 norms are built to flag a child whose patterns lag that schedule.
An Australian community cohort study published in Developmental Medicine and Child Neurology in 2015 assessed 1,494 four-year-olds and found a speech sound disorder prevalence of 3.4 percent, with 40.8 percent of those children also showing a language disorder and 20.8 percent showing poor pre-literacy skills. ASHA cites a similar 40 percent overlap with language impairment. That overlap is why a clinician who scores a KLPA-3 will often also give a broader language measure, such as the one described in our article on the CELF-5.
The long-term stakes are mostly about reading. A longitudinal study by Robin Peterson, Bruce Pennington, Lawrence Shriberg, and Richard Boada followed 86 children with speech sound disorders from ages 5 to 6 through ages 7 to 9 and found elevated rates of reading disability, with the strongest risk in children who also had language impairment.
Is the KLPA-3 an IQ test?
No. The KLPA-3 measures one narrow thing: how often a child's speech departs from adult pronunciation in rule-governed ways. An intelligence test measures reasoning, knowledge, working memory, and processing speed across many types of problems. A KLPA-3 standard score cannot be read as a proxy for an IQ score. Both do use a mean of 100 and a standard deviation of 15, which can confuse a parent who sees both numbers on one evaluation report. The shared metric only means the two scores are expressed in the same units relative to their own norm groups.
The two kinds of testing meet in a full evaluation. The Peterson study found that phonological awareness alone predicted later literacy "less well than a model that also included syntax and nonverbal IQ," which is one reason a school or clinic may pair speech testing with an individually administered cognitive assessment when a child's learning is a concern. The KLPA-3 contributes the speech piece of that picture and nothing more.
For adults curious about their own reasoning ability, the RIOT IQ test, the Reasoning and Intelligence Online Test developed by RIOT IQ with psychometrician Dr. Russell T. Warne, is a separate tool for a separate purpose. It is designed for adults 18 and older, uses 15 subtests across six cognitive indices (verbal reasoning, fluid reasoning, spatial ability, working memory, processing speed, and reaction time), takes about 52 minutes, and reports scores on the same mean-100, standard-deviation-15 scale. It measures general cognitive ability rather than speech, and it does not replace an individually administered diagnostic evaluation. Readers can learn more at RIOT IQ.
Limitations to keep in mind
• Single-word sampling: because the KLPA-3 is scored from 60 single words, it inherits the limit ASHA attaches to that method: single-word testing "may or may not reflect the same sound production as connected speech." Clinicians typically add a conversational speech sample.
• Dialect: Pearson states that sound changes judged to be dialectal variations are not scored as errors on the GFTA-3 and so are not assigned phonological processes on the KLPA-3. Clinician judgment about a child's linguistic community drives that decision.
• Professional use only: Pearson sells the KLPA-3 at Qualification Level B, which restricts purchase to trained professionals.
Frequently asked questions
What does KLPA-3 stand for?
Khan-Lewis Phonological Analysis, Third Edition, named for authors Linda M. L. Khan and Nancy P. Lewis. Pearson published it in 2015.
What age range does the KLPA-3 cover?
Pearson lists the age range as 2 years 0 months through 21 years 11 months, the same range as the GFTA-3 it depends on.
Can the KLPA-3 be given on its own?
No. The KLPA-3 is an analysis of responses to the 60 Sounds-in-Words items of the GFTA-3.
What scores does the KLPA-3 report?
A standard score with a mean of 100 and a standard deviation of 15 based on age and sex norms, a 95 percent confidence interval, a percentile rank, an age equivalent, and a percent-of-occurrence figure per core process.
Who administers and scores the KLPA-3?
Speech-language pathologists and other professionals who meet Pearson's Qualification Level B, by hand or through Pearson's Q-interactive or Q-global platforms.
References
1. Pearson. (n.d.). KLPA-3: Khan-Lewis Phonological Analysis, Third Edition. pearsonassessments.com
4. American Speech-Language-Hearing Association. (n.d.). Speech sound disorders: Articulation and phonology (Practice Portal). asha.org
5. Crowe, K., & McLeod, S. (2020). Children's English consonant acquisition in the United States: A review. American Journal of Speech-Language Pathology, 29(4), 2155-2169. pubmed.ncbi.nlm.nih.gov
6. Eadie, P., Morgan, A., Ukoumunne, O. C., Ttofari Eecen, K., Wake, M., & Reilly, S. (2015). Speech sound disorder at 4 years: Prevalence, comorbidities, and predictors in a community cohort of children. Developmental Medicine and Child Neurology, 57(6), 578-584. pubmed.ncbi.nlm.nih.gov
7. Peterson, R. L., Pennington, B. F., Shriberg, L. D., & Boada, R. (2009). What influences literacy outcome in children with speech sound disorder? Journal of Speech, Language, and Hearing Research, 52(5), 1175-1188. pmc.ncbi.nlm.nih.gov
Hero photo: Wooden alphabet blocks and shape toys on a table. U.S. Air Force, Airman 1st Class Hannah Stubblefield photo, public domain, via Wikimedia Commons (cropped).
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