The Verbal Comprehension Index, read as a score and not as a talent

0 The short answer

The Verbal Comprehension Index (VCI) is a composite standard score, mean 100 and standard deviation 15, built from a small set of verbal subtests, and it is best read as a measure of acquired language knowledge that is largely saturated with general ability, not as a pure verbal talent. The WAIS-5 builds its primary VCI from two subtests (Similarities and Vocabulary), the WAIS-IV used three (Similarities, Vocabulary and Information), and ACIS builds its own VCI from five (Antonyms, Vocabulary, Information, Synonyms and Similarities), which the Custom Test returns for 25 dollars and the Full Scale form (50 dollars, about 175 minutes) also reports (prices read October 29, 2026). The decisive limit is that a VCI reflects the language and schooling behind it, so an English only, online, unsupervised index is a normed estimate of your standing on those tasks and not a clinical or diagnostic result.

1 What is the Verbal Comprehension Index?

The Verbal Comprehension Index is a composite score that converts the sum of a few verbal subtest scores into a standard score, a percentile rank and a confidence interval, and it is one of the primary indexes of the Wechsler scales. Pearson's brochure for the WAIS-5, read October 29, 2026, describes a primary battery of 10 subtests that appraise intellect in five cognitive domains: verbal comprehension, visual spatial, fluid reasoning, working memory and processing speed. Its WAIS-IV product page, read the same day, describes four: verbal comprehension, perceptual reasoning, working memory and processing speed. The WISC-V product page for children aged 6 to 16 lists five primary index scores, among them the Verbal Comprehension Index.

An index is not an average of raw results. Each subtest first becomes a scaled score on a scale with a mean of 10 and a standard deviation of 3 (Canivez and colleagues, 2026). The scaled scores in the index are added and the sum is converted to the index scale, where, in the words of the same paper, index scores and the Full Scale IQ are standard scores with a mean of 100 and a standard deviation of 15. Pearson's sample WAIS-5 score report, a document for a fictional examinee read October 29, 2026, shows the result for the VCI in one row: the sum of scaled scores, the composite score, the percentile rank, a 95 percent confidence interval, a qualitative description and a standard error. The report states that confidence intervals are calculated using the Standard Error of Estimation. Reading a VCI therefore means reading a range with a label attached, never a single point.

The name carries a theory. In the Cattell-Horn-Carroll (CHC) vocabulary, verbal knowledge tasks belong to comprehension-knowledge, abbreviated Gc, which the ACIS technical manual describes as the primary foundation of its own VCI. Cattell's 1963 paper in the Journal of Educational Psychology, titled "Theory of fluid and crystallized intelligence: A critical experiment," is the usual starting point for that lineage. The page on the CHC model lists the broad abilities, and the page on crystallized intelligence testing covers the ability itself: what Gc is, how it changes across a lifetime and which task families sample it. This page stays on the index as a score, meaning what feeds it, how it is reported and how far it can be trusted.

Two other pages belong beside this one. The page on verbal IQ as an ability test covers how a verbal score is built when several verbal tasks are combined, and the page on the older verbal versus performance split covers the history of the two IQs that the index scores replaced. The comparison that matters most for a reader is narrower and practical: if two people have the same VCI, are they the same in verbal ability? Not necessarily, and the sections below explain why.

2 Which subtests feed the VCI in the WAIS-5, the WAIS-IV and the WISC-V?

The same index name sits on different subtest sets in different editions, so a VCI from one scale cannot be compared point for point with a VCI from another without knowing its recipe. The table below uses only Pearson's own documents, each read October 29, 2026. It lists subtests by name and reproduces no item, score table or norm.

Three details sit behind the table. First, the WAIS-5 brochure draws two lists: a Full Scale list in which the Verbal Comprehension domain holds Similarities, Vocabulary, Information and Comprehension, and a Primary Index Scales list in which Verbal Comprehension holds Similarities and Vocabulary only. In the sample score report the VCI row carries a sum of scaled scores of 29, which matches a Similarities score of 14 and a Vocabulary score of 15 printed on the same page, so the two subtests are the entire primary VCI there. The same report shows Information and Comprehension in parentheses, which, by its legend, marks secondary subtests. Pearson's WAIS-5 product page adds that the FSIQ now has only seven subtests, fewer than the 10 subtests that feed the primary indexes.

Second, the WAIS-IV page names Information as a core subtest and Comprehension as supplemental, and states that one supplemental subtest per index may be substituted. The page on the WAIS-IV walks through its 15 subtests and four index scores, and the page on the WAIS-5 subtests does the same for the newer scale. Third, the WISC-V sample score report prints the Verbal Comprehension scale as Similarities and Vocabulary, with Information and Comprehension in parentheses, and shows the VCI sum of scaled scores as the sum of those two.

Why does the recipe matter to a reader? A shorter recipe samples less of the construct and is more exposed to one weak or lucky result. A two subtest VCI is also weighted toward two tasks, Similarities and Vocabulary, with no general information component unless the full scale list is used. The WAIS-IV recipe added Information, which brings general knowledge into the index. Neither design is wrong. They simply answer slightly different questions, which is why a score should travel with the name of the test and the edition that produced it.

3 What does a VCI of a given size mean in percentiles?

A VCI converts to a percentile through the normal curve with mean 100 and standard deviation 15, so 100 is the median, 115 sits near the 84th percentile and 130 near the 98th, but those percentiles describe rank among the norm group, not an amount of anything. The conversions in the table are our arithmetic from the normal distribution with mean 100 and standard deviation 15, rounded to one decimal place. Real norm tables are built from the test's own standardization data and can differ slightly, especially in the tails. The page on how IQ scores are normed explains how norm tables are built, and the page on why standard deviation 15 matters explains the scale itself.

Two cautions apply. The first is that percentiles are not evenly spaced. Moving from 100 to 110 passes about 25 percentile points, while moving from 130 to 140 passes about 2. A reader who compares a VCI of 128 with a VCI of 134 is comparing two points that differ by about 2 percentile points, which is well inside the uncertainty of a single administration. The page on why IQ scores and percentiles cannot be averaged explains why the two scales should never be mixed, and the IQ percentile calculator converts in both directions. For the other side of the table, the rarity calculator turns a score into a one in N figure.

The second caution concerns labels. Pearson's sample reports print a qualitative description beside each composite. In the WAIS-5 sample, a VCI of 124 is labeled "Very high," and the FSIQ of 111 in the same report is labeled "Above average." These are Pearson's descriptors for that publication, and different publishers and different clinicians word the bands differently, so the useful quantity is the number and its interval, not the adjective.

4 How does the VCI relate to the Full Scale IQ and the GAI?

The VCI is one input to the Full Scale IQ, and the General Ability Index (GAI) is a second summary that keeps the verbal and reasoning content while setting aside working memory and processing speed. Pearson's presentation on the Wechsler General Ability Index, read October 29, 2026, states that the GAI is an optional index score for the WISC-IV and the WAIS-IV and that it is derived from the core Verbal Comprehension and Perceptual Reasoning subtests. It also describes the GAI as an estimate of general intellectual ability with reduced emphasis on working memory and processing speed relative to the FSIQ. The same presentation lists the WAIS-IV structure for the GAI and its counterpart, the Cognitive Proficiency Index (CPI): the six verbal and perceptual reasoning subtests feed the GAI, while Digit Span, Arithmetic, Symbol Search and Coding feed the CPI.

That structure shows why the VCI carries more weight in the GAI than in the Full Scale IQ. In the WAIS-IV, three of the six subtests that make up the GAI are verbal, while three of the ten subtests behind the FSIQ are verbal. The page on the General Ability Index works through the comparison of the GAI with the Full Scale IQ, and the page on the Cognitive Proficiency Index covers its counterpart, the CPI, built from working memory and processing speed. The same presentation warns against one myth: that the GAI is simply the FSIQ without working memory and processing speed. It states that the GAI still taps those abilities, to a lesser degree than the FSIQ, because cognitive abilities are interrelated.

For the WAIS-5, the pattern is similar but the recipe changed. Pearson's brochure lists the General Ability Index (GAI), the Cognitive Proficiency Index (CPI), a Nonverbal Index, a Nonmotor Index and a Verbal Reasoning Index among its ancillary scales, and its product page says the FSIQ now has seven subtests. The brochure does not state which seven, and this page does not guess. The practical rule for a reader is therefore simple. The VCI is a verbal part score, the FSIQ is the broad summary, and the GAI sits between them for people whose speed and working memory scores would otherwise pull a reasoning and knowledge summary down.

The ACIS reports follow the same logic. The technical manual, read October 29, 2026, lists a General Ability Index among the composites that ACIS reports when their subtests are available, and says it emphasizes higher order reasoning and knowledge while reducing dependence on working memory and processing speed. Its form availability table shows the GAI on the Optimized and Full Scale forms and a short form Full Scale IQ on the Quick form. The page on what a Full Scale IQ is explains the summary score, and the manual itself holds the definitions without this page quoting a statistic from it.

5 How much does the VCI tell you beyond general intelligence?

An independent factor analysis of the WAIS-5 finds that most of the shared variance in the verbal subtests belongs to the general factor, so a VCI is a mixture of general ability and a smaller verbal specific component. The most direct evidence for the current scale is the February 2026 paper by Gary Canivez, Marley Watkins, Ryan McGill and Stefan Dombrowski in Assessment. They analyzed the published WAIS-5 standardization correlations (N = 2,020, ages 16 to 90) for the 20 primary and secondary subtests with exploratory and confirmatory methods, and they note that the publisher's technical manual did not include exploratory analyses, confirmatory models with fewer than five first-order factors, or rival bifactor models.

Their abstract reports that exploratory results did not support five latent factors with separate Visual Spatial and Fluid Reasoning factors. A four factor model was supported instead, with those two merged into a Perceptual Reasoning factor and with measurement dominated by a general intelligence (g) factor, similar to the WAIS-IV structure. The Verbal Comprehension factor itself did survive in their solution, which is worth saying plainly: verbal subtests do cluster together beyond g. The question is how much unique signal that cluster carries.

Their variance table answers it. In the Schmid-Leiman solution for the total sample, the general factor accounted for 40.4 percent of the total variance and the Verbal Comprehension group factor for an additional 4.4 percent. Of the common variance, the general factor accounted for 72.0 percent and Verbal Comprehension for 7.9 percent. In the same table the four verbal subtests (Similarities, Vocabulary, Information and Comprehension) have standardized loadings on g between .655 and .676 and on the verbal group factor between .398 and .531. The omega-hierarchical subscale coefficient for Verbal Comprehension was .283, against a minimum of .50 that the authors apply, while the coefficient for g was .877. The authors conclude that unit-weighted composites of the group factors carry too little unique true score variance for confident clinical interpretation, and they write that the VCI is a mixture of general intelligence variance and some unique verbal comprehension variance.

For a reader this changes how to use a VCI. A high VCI beside a high FSIQ mostly says the same thing twice. A VCI that sits well above or below the other indexes is more informative, but it is also the result that most needs support from the subtests underneath it, as the later section on reading your own result explains. The page on what IQ measures covers the general factor that this variance table is built around.

6 What lowers or raises a VCI for reasons unrelated to reasoning?

Language background, years of schooling and reading history all move verbal scores because the subtests sample learned words and facts, so a VCI describes a person together with the circumstances in which the words were learned. Three influences can be separated.

Vocabulary size varies widely even among native speakers. Brysbaert and colleagues, in a 2016 paper in Frontiers in Psychology, estimate that an average 20 year old native speaker of American English knows 42,000 lemmas (a word and its inflected forms counted as one), with numbers ranging from 27,000 lemmas for the lowest 5 percent to 52,000 for the highest 5 percent, and with about 6,000 more lemmas learned between ages 20 and 60. Those figures describe native speakers, and the abstract does not extend them to second language learners. They matter here because a vocabulary subtest can sample only a small part of that range of words.

Schooling raises measured ability. Ritchie and Tucker-Drob's 2018 meta-analysis in Psychological Science covered 142 effect sizes from 42 data sets with over 600,000 participants, drawn from quasiexperimental designs. It found consistent evidence for effects of education on cognitive abilities of approximately 1 to 5 IQ points for an additional year of education, with effects persisting across the life span and present on all broad categories of ability studied. The study concerns education broadly, not verbal indexes specifically, and an average effect across studies does not tell any one reader how many points their own schooling added. What it supports is a cautious reading of an index: a verbal score partly records the education a person received, so comparing two people with very different schooling by VCI alone compares more than their reasoning.

Language of testing is part of the construct. The ACIS technical manual states that verbal and knowledge tasks can be affected by English proficiency and educational exposure, and describes Gc as strongly affected by English proficiency, educational exposure and cultural knowledge. The Standards for Educational and Psychological Testing say, in Standard 3.13, that a test should be administered in the language most relevant and appropriate to the test purpose, and add in the comment that users should take into account the linguistic and cultural characteristics and relative language proficiencies of examinees who are bilingual or use multiple languages (AERA, APA and NCME, 2014, read October 29, 2026). A person who learned English as an adult is not less able than a native speaker because an English vocabulary score is lower, but the score may no longer measure what it was built to measure for that person. The page on IQ tests for non-native English speakers covers what moves a score for readers whose first language is not English.

When language is a concern, a verbal index is therefore best read beside indexes that rely less on words, such as perceptual reasoning or fluid reasoning. A gap between them is a prompt to ask questions about language and schooling, not a diagnosis, and no group statistic on this page describes any individual reader.

7 How does the VCI change across adulthood?

Verbal knowledge measures tend to peak later in adulthood than speeded and memory measures do, so an age referenced VCI and a raw level of knowledge can tell different stories. Hartshorne and Germine's 2015 paper in Psychological Science combined data from 48,537 online participants with a comprehensive analysis of normative data from standardized IQ and memory tests, and reports considerable heterogeneity in when abilities peak: some abilities peak and begin to decline around high school graduation, some plateau in early adulthood and decline from the 30s, and still others do not peak until the 40s or later. In the full text, the vocabulary peak came at about age 50 in the WAIS-III normative sample, which consisted of 2,450 healthy Americans aged 16 to 89, and later, at about 65, in their web based data. The authors say the five tasks that invoke learned knowledge peaked significantly later than nearly every other task.

Two points follow for a VCI. First, because a Wechsler index is referenced to a person's own age group, the same raw performance can map to different index scores at different ages, and the direction depends on how the group average moves with age. Pearson's WAIS-5 sample score report makes the reference visible by printing a second scaled score for each subtest, a reference group scaled score based on examinees aged 20:0 to 34:11, next to the age based one. Second, the web and standardization samples disagree on the peak age by about 15 years, and the paper says that could point to confounds or to cohort differences between the two datasets. Cross sectional comparisons of this kind mix aging with generational change.

For the person reading a VCI, the useful reading is relative: the score says where you stand among people of your age on the sampled knowledge, and the reference group score, where one is reported, says where you stand among young adults. Neither says that verbal ability will rise or fall for you.

8 How can an adult obtain a normed VCI?

An adult can obtain a normed VCI from a psychologist who gives a Wechsler scale or from a normed online battery that reports a verbal index, and the options differ most in supervision, interpretation and how many subtests stand behind the number. The table below sets them side by side. ACIS prices and times were read on October 29, 2026 and can change. Cells marked "not stated" mean the sources read gave no figure.

The clinician route remains the reference for any decision that has consequences. A supervised session lets a professional observe effort, language fluency and distractions, and a clinician can interpret a pattern in light of a history that no website has. The page on where to take an IQ test compares the supervised and unsupervised paths, the page on IQ tests for adults is the entry point for adults choosing a test, and the page on the best online IQ tests compares the online batteries. A brief intelligence test from another publisher is covered on the page on the KBIT-2.

Free quizzes answer a different question. They sample words or facts, often return a label without a percentile, and rarely state a norm group, so they do not produce a VCI in any sense this page uses. A reader who wants a broader screen of several abilities at once, which would put a verbal index beside the others, can start from the page on the cognitive ability test.

ACIS is a seller in this market, so this section is a disclosure as well as a comparison. The table shows where the options differ. Only the clinician route is supervised and clinically interpreted. The ACIS rows are online and unsupervised, and the ACIS norm frame is English. A buyer should choose the clinician route for any result that must stand up to a school, an employer or a diagnosis, and a normed online battery for personal insight.

9 What does the ACIS Verbal Comprehension Index consist of?

The ACIS Verbal Comprehension Index is built from five subtests, Antonyms, Vocabulary, Information, Synonyms and Similarities, and each samples verbal knowledge through a different format. All five are reported as scaled scores (mean 10, standard deviation 3), and together they yield the index on the scale with mean 100 and standard deviation 15, with a percentile and a 95 percent confidence interval. The technical manual, read October 29, 2026, describes the VCI as the access and application of acquired verbal knowledge, a primary index. Each subtest has its own page, and the pages describe the construct without disclosing items.

The Vocabulary page frames the task as how precisely a person understands words and how well those meanings can be explained or recognized. In the manual the examinee is shown a word and types its definition in their own words, with 45 words and 1 minute 30 seconds per item, and credit that depends on the precision and completeness of the definition. The Antonyms page describes precision in word meaning and the ability to separate a term from its opposite. In the manual this is a multiple choice section of 31 words under one continuous 10 minute limit, so distributing effort across items is part of the task. The Synonyms page describes meaning equivalence, and the manual gives it 31 questions in a 10 minute whole section limit, with single word stimulus and options so that sentence context gives no help.

The Information page describes general knowledge accumulated over time and retrieved without lengthy problem solving. In the manual the answers are typed, there are 30 questions, and each advances automatically after 30 seconds. The Similarities page describes verbal concept formation. The manual gives it 31 pairs at 1 minute 30 seconds per item, with a produced explanation scored from 0 to 2 points: a superordinate category that captures both members earns full credit and a concrete or functional resemblance earns partial credit. The manual says that scoring distinction is what separates induction from lexical knowledge alone, which is why Similarities is the verbal subtest with the closest bridge to reasoning. The pages and the manual state no total administration time for the five together, so none is given here.

None of the five is among the three subtests that present items as audio (Digit Span, Alphanumeric Sequencing and Arithmetic), so working sound is not a requirement for this index. Which form contains which subtest decides what the report can show, and the manual's availability matrix is explicit:

• Quick (15 dollars, about 45 minutes) holds two of the five, Similarities and Vocabulary, and reports a partial verbal index.
• Optimized (30 dollars, about 110 minutes) holds four, all but Information, also a partial index.
• Full Scale (50 dollars, about 175 minutes) holds all five and reports the full VCI.
• Custom Test (5 dollars per subtest) lets a buyer pick any subtests, and its description states that "any domain you complete returns its full index score, and every subtest returns its scaled score." Five verbal subtests at 5 dollars each is 25 dollars, our arithmetic on the posted price. The Full Scale form costs the same as ten Custom subtests, so a buyer who wants more than ten should take the Full Scale form.

The manual also lists a composite called VKI that "combines Antonyms, Synonyms, Vocabulary, and Information," available on the Full Scale form because it needs those four subtests. It is a separate score from the VCI: it leaves out Similarities, the subtest with the reasoning bridge. The free trial needs no card and is limited to one per person. As read on the site on October 29, 2026, it does not include the five verbal subtests, so it will not return a VCI, and the Custom Test is the direct path to this index. The example reports for the Quick, Optimized and Full Scale forms show what each form prints. The technical manual holds the full definitions, and this page quotes no statistics from it.

10 How should you read your own VCI?

Read a VCI in four steps: confirm which subtests and which edition produced it, read the interval before the point estimate, look at the subtests underneath, and compare it with the other indexes only after that. Each step guards against a specific over-reading.

Step one: the recipe. As the earlier table shows, a WAIS-5 VCI rests on two subtests and a WAIS-IV VCI on three, so two reports with the same VCI are not interchangeable.

Step two: the interval. Pearson's sample reports print a 95 percent confidence interval for every composite, built from the Standard Error of Estimation. In the WAIS-5 sample, a VCI of 124 carries an interval of 115 to 130, which is 15 points wide (our arithmetic). The point estimate is the center of a range in which the person's standing on the construct plausibly sits. The page on reliability versus validity explains why every score has such a range and what a reliability coefficient does and does not promise.

Step three: the subtests. The index hides how it was assembled. On a two subtest Wechsler VCI, scaled scores of 11 and 11 and scaled scores of 15 and 7 have the same sum, so they convert to the same index. The ACIS manual gives profile reading rules for its five verbal subtests: when Information is high with Vocabulary and Synonyms, the profile supports broad verbal knowledge strength; when Information is lower than Vocabulary, a person may have strong word meaning with narrower factual exposure; when Antonyms is high and Similarities lower, the profile may show strong word knowledge with less semantic relation reasoning. These describe profile shapes and are not diagnoses.

Step four: the other indexes. Pearson's WAIS-5 sample report compares the VCI with the mean of the five index scores and with every other index, and for each comparison it prints a critical value at the .05 level and a base rate. The report's own design makes a point that readers often miss: a difference can be statistically significant and still occur in a sizeable share of people. In the sample, the VCI difference from the mean of the indexes is flagged as a strength with a base rate of 5 percent or less, while the pairwise differences carry base rates running from 25 percent or less to 5 percent or less. The page on how often index scores differ gives the general context a single gap needs, because uneven profiles are common. When the fluid reasoning index and the verbal index disagree, the page on the Fluid Reasoning Index is the place to look for what the other side of the gap measures.

A VCI is also a poor basis for one conclusion that readers draw from it. People often treat a high VCI as proof of a verbal gift and a low one as proof of poor language skill. The variance evidence earlier shows why neither follows: much of the index is general ability, and what is left reflects exposure to words and facts.

11 What conditions matter in an unsupervised session?

An unsupervised VCI is only as good as the conditions of the session, and for verbal tasks the conditions that matter are the language of testing, uninterrupted time and the absence of lookup help. The technical manual, read October 29, 2026, says that online administration requires careful interpretation and names factors such as device, screen size, visual clarity, distraction, fatigue and motivation. For verbal and knowledge tasks it adds that English proficiency and educational exposure can affect the result.

Some practical points follow from the format of the five ACIS verbal subtests, as the manual describes them:

• Pacing differs by subtest. Antonyms and Synonyms run under one continuous 10 minute limit for the whole section, so time not spent on a hard word is time available for later ones. Vocabulary, Similarities and Information have per item limits (1 minute 30 seconds, 1 minute 30 seconds and 30 seconds), so each item has its own allowance.
• Typed answers need a real keyboard. Vocabulary, Information and Similarities ask for typed responses. A full size keyboard and a window with no other tabs open remove avoidable friction.
• No sound is needed for this index. The audio subtests belong to other indexes. A full session on the Full Scale form does need working sound for those, as noted above.
• Do not look words up. A dictionary or a search engine mid-test makes the score describe the tool. The norm assumes the person alone.
• Use the breaks. ACIS allows breaks, saves progress between subtests and gives 30 days to complete, so a session of about 175 minutes does not have to be one sitting. Fatigue lowers retrieval even on tasks that are not speeded.

For readers whose first language is not English, the guidance is the same as above: take the result as a description of English verbal performance, not as a statement about intelligence in general.

12 Where ACIS sits, and what a buyer should do

ACIS offers a normed, five subtest Verbal Comprehension Index at a one time price, but it is an online, unsupervised, English only instrument that is not clinical or diagnostic and not for hiring, school accommodations or admission to high IQ societies. Stating the limits first is a matter of fit, not caution: a buyer who needs a score for any of those uses needs a supervised assessment by a qualified professional, and the comparison table earlier on this page sets out the paths.

The Standards for Educational and Psychological Testing (AERA, APA and NCME, 2014), which the three sponsoring bodies publish and which the 2014 edition makes open access, set out what a reader should ask of any score. Standard 1.14 says that when interpretation of subscores, score differences or profiles is suggested, the rationale and relevant evidence in support of such interpretation should be provided, and that where composites are developed, the basis and rationale for arriving at the composites should be given. Standard 2.3 says that for each total score, subscore or combination of scores that is to be interpreted, estimates of relevant indices of reliability and precision should be reported. Standard 3.13 says a test should be administered in the language that is most relevant and appropriate to the test purpose. Read together, they define a fair question for any VCI, ACIS's or anyone else's: what does it combine, how precise is each score that is reported, and was it given in a language the person knows well? The ACIS answers sit in the technical manual, which this page points to and does not quote for statistics.

The APA's own guidance points the same way. In the Ethical Principles of Psychologists and Code of Conduct (read October 29, 2026), Standard 9.06 says psychologists interpreting assessment results take into account the purpose of the assessment and the test factors, test-taking abilities and other characteristics of the person assessed, including linguistic and cultural differences, and indicate any significant limitations of their interpretations. Standard 9.02(c) says they use assessment methods appropriate to an individual's language preference and competence, unless an alternative language is relevant. Those standards bind psychologists, not a self administered website, but they describe the care a reader should apply to their own result.

What a buyer should do depends on the question:

1. If you want to know your standing on verbal knowledge tasks for personal insight, take the Custom Test with the five verbal subtests (25 dollars) or the Full Scale form (50 dollars), and read the index with its interval and the five scaled scores.
2. If you want a broad profile with a verbal index beside the others, the Full Scale form reports the six indices and composites such as the GAI, while Quick and Optimized report partial verbal indexes from two and four subtests.
3. If your first language is not English, read the VCI as an English language result, and read it beside indexes that rely less on words.
4. If a school, an employer or a clinician needs the result, go to a qualified professional for a Wechsler scale.
5. If you only want to try the format, the free trial needs no card and is limited to one per person, though it does not include the verbal subtests.

ACIS states a refund term in its own words: "Full refund within 5 days if the report does not deliver the features described at checkout or a technical issue prevents you from accessing your results." That is a conditional guarantee, not an unconditional one. Prices were read on October 29, 2026 and can change, and the form pages show the current ones.

13 Sources Behind This Page

Every figure above is traceable to one of the following, and each is linked at the point where it is used. Web pages and documents were read on October 29, 2026. The percentiles in the percentile table, the 15 point interval width and the 25 dollar total are our arithmetic on a normal curve with mean 100 and standard deviation 15, on a published interval and on the posted Custom Test price, and are labeled as such in the text.

• AERA, APA and NCME. Standards for Educational and Psychological Testing. American Educational Research Association, 2014 (Standards 1.14, 2.3 and 3.13).
• American Psychological Association. Ethical Principles of Psychologists and Code of Conduct, effective January 1, 2017, Standards 9.02 and 9.06.
• Brysbaert M, Stevens M, Mandera P and Keuleers E. How Many Words Do We Know? Practical Estimates of Vocabulary Size Dependent on Word Definition, the Degree of Language Input and the Participant's Age. Frontiers in Psychology, 2016, volume 7, article 1116.
• Canivez G, Watkins M, McGill R and Dombrowski S. Construct Validity of the WAIS-5: Complementary Exploratory and Confirmatory Factor Analyses of the 20 Primary and Secondary Subtests. Assessment, advance online publication, 2026, pages 1 to 27.
• Cattell R. Theory of fluid and crystallized intelligence: A critical experiment. Journal of Educational Psychology, 1963, volume 54, issue 1, pages 1 to 22.
• Hartshorne J and Germine L. When Does Cognitive Functioning Peak? The Asynchronous Rise and Fall of Different Cognitive Abilities Across the Life Span. Psychological Science, 2015, volume 26, issue 4, pages 433 to 443.
• Pearson. WAIS-5 overview brochure, read October 29, 2026.
• Pearson. Wechsler Adult Intelligence Scale, Fifth Edition (WAIS-5) product page, read October 29, 2026.
• Pearson. WAIS-5 sample score report, dated September 16, 2024, fictional examinee, read October 29, 2026.
• Pearson. Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV) product page, read October 29, 2026.
• Pearson. Wechsler Intelligence Scale for Children, Fifth Edition (WISC-V) product page, read October 29, 2026.
• Pearson. WISC-V sample score report, fictional examinee, read October 29, 2026.
• Ritchie S and Tucker-Drob E. How Much Does Education Improve Intelligence? A Meta-Analysis. Psychological Science, 2018, volume 29, issue 8, pages 1358 to 1369.
• Zhu J, Raiford S and Coalson D, with Saklofske D as discussant. The What, When, and How of the Wechsler General Ability Index. Pearson presentation, copyright 2007, read October 29, 2026.
• ACIS. Technical Manual, read October 29, 2026 (definitions, form availability matrix and subtest formats only; no statistics are quoted on this page).

14 Frequently Asked Questions