What a quantitative reasoning index really combines

0 The short answer

A Quantitative Reasoning Index (QRI) is a score built from a fixed pair of subtests, and on the Wechsler scales it is an ancillary index made from Figure Weights and Arithmetic, not one of the primary indexes. Pearson lists it for the WISC-V (ages 6:0 to 16:11) and for the WAIS-5 (ages 16:0 to 90:11), while ACIS reports a QRI as one of its six primary indices, built from Mathematical Achievement and Arithmetic and available on the Full Scale form (50 dollars, about 175 minutes) or in a Custom Test (10 dollars for both subtests), prices read October 29, 2026. The names match and the contents do not, so a QRI from one battery cannot be read against another battery's. The decisive limit is that two subtests give a coarse score: a QRI far from the other indices is a prompt to look at the two subtests and the circumstances, never a verdict, and an online unsupervised index is not a clinical instrument.

1 What is a Quantitative Reasoning Index?

A Quantitative Reasoning Index is a standardized composite that summarizes performance on a defined set of quantitative subtests, which means it is a calculation made after testing and not a test a person sits. Nobody takes a QRI. A person takes subtests, each one produces a scaled score, and the publisher adds the scaled scores of the subtests assigned to the index and converts the sum to a score on the same standard scale as the other composites. Pearson's WISC-V page states the recipe for its version in one sentence: the QRI is derived from the sum of scaled scores for the Figure Weights and Arithmetic subtests, and the page calls it an indicator of the child's quantitative reasoning skills (read October 29, 2026).

Two ideas in that definition deserve attention before anything else. The first is that "quantitative reasoning" in the index name is a label chosen by the publisher for a pair of tasks, and what the label covers depends on which two tasks were paired. The second is that an index is only as broad as its subtest list. A QRI with two subtests is a narrow sample of what the Cattell-Horn-Carroll (CHC) model calls quantitative ability, and the page on the CHC model shows how that model separates quantitative knowledge (Gq) from fluid reasoning (Gf). The technical language is worth one definition now. Riverside Insights, publisher of the Woodcock-Johnson V, describes Gq in its CHC descriptions for the WJ V cognitive battery as the depth and breadth of declarative and procedural knowledge related to mathematics, such as mathematical symbols, operations and computational procedures. The same document describes quantitative reasoning (RQ), a narrow ability, as the ability to reason, by induction or deduction, with quantities, mathematical relations and operators. An index called "quantitative reasoning" can sample either ability or a blend, and the two Wechsler subtests and the two ACIS subtests do not blend them in the same proportion.

The scale is the familiar one. ACIS reports indices and the Full Scale IQ on a standard scale with a mean of 100 and a standard deviation of 15, and the page on why the standard deviation is 15 explains what that means for how far a score sits from the average. A QRI of 115 therefore says that the person scored about one standard deviation above the norm group on that pair of subtests, which the page on the difference between an IQ score and a percentile turns into a rank. The index does not say how that person solves problems, how well they were taught or how they feel about mathematics. It says how a defined pair of tasks went on one day, compared with a defined group.

2 Which batteries report a QRI, and with which subtests?

Three documented batteries report a QRI that Pearson or ACIS defines, the WISC-V, the WAIS-5 and ACIS, and the first two give it the same two subtests while ACIS gives it a different pair. The table below lists what each publisher's own pages say, read October 29, 2026, and says plainly where a page is silent.

Three points need a sentence each. First, the WISC-V and WAIS-5 rows rest on different kinds of evidence. For the WISC-V, Pearson's product page names the QRI and its subtests in words. For the WAIS-5, the Pearson product page lists quantitative reasoning among fourteen new ancillary index scores without naming its subtests in the text read, and the composition comes from the ancillary index flyer, whose table places Figure Weights and Arithmetic under the heading Quantitative Reasoning. The overview brochure lists the Quantitative Reasoning Index (QRI) among the domain specific ancillary scores.

Second, the absence of a QRI in the WAIS-IV is a statement about the one document opened, not about everything Pearson published for that edition. Pearson's WAIS-IV sample score report groups Arithmetic with Digit Span in its working memory subtest summary and contains no quantitative index. The sibling page on the Working Memory Index follows Arithmetic out of that index between the two adult editions, and the page on the WAIS-5 subtests follows each Wechsler subtest to the scores it feeds.

Third, the rows are not equivalents. The table says which two tasks are paired, and it does not say the pairs measure the same thing. Figure Weights is a reasoning task and Arithmetic is a calculation task that leans on memory, as the next sections show, while ACIS pairs a school mathematics subtest with the same kind of calculation task. The two pairs share only the name Arithmetic, and each publisher writes its own items, so even the shared name does not make the subtest the same. Pearson's pages do not describe the content of its items, and this page does not either.

3 Why do the Wechsler scales keep the QRI ancillary?

Pearson keeps the QRI outside the primary indexes because its second subtest, Arithmetic, does not sit cleanly in any one primary index, and the publisher says so itself. The clearest statement is in the frequently asked questions of the WISC-V page, which ask how the interpretation of Arithmetic changes now that it is classified as a fluid reasoning subtest. Pearson answers that it would be inappropriate to interpret Arithmetic as a measure of only fluid reasoning or only working memory, which is why it does not contribute to any primary index score. The same answer calls Arithmetic a highly g loaded and factorially complex subtest, reports that a five factor model with Arithmetic on the fluid reasoning factor fit better, and adds that models with Arithmetic on the working memory factor also had merit. It says Arithmetic has a substantial cross loading on working memory, a slightly higher loading on fluid reasoning, and a cross loading on verbal comprehension (page read October 29, 2026).

That statement explains the architecture. The WISC-V Full Scale IQ is based on seven subtests: Similarities, Vocabulary, Block Design, Matrix Reasoning, Figure Weights, Digit Span and Coding. Figure Weights is in that list and Arithmetic is not. The ancillary indexes, in Pearson's wording, are derived from combinations of primary subtests or of primary and secondary subtests. The QRI is that kind of index: one subtest that feeds a primary index and the Full Scale IQ, paired with one that feeds neither. For adults, the Pearson WAIS-5 page describes a seven subtest Full Scale IQ (45 minutes) and ten primary index subtests (about 60 minutes). The overview brochure lists Matrix Reasoning, Figure Weights, Arithmetic and Set Relations under fluid reasoning in the full test framework, and only Matrix Reasoning and Figure Weights under the primary Fluid Reasoning Index. Arithmetic is in the framework and outside the primary scores.

Two consequences follow for anyone reading a QRI. The first is that the QRI sits among the ancillary scores, which Pearson's WAIS-5 page says augment the primary indexes, the General Ability Index and the Full Scale IQ, and which the sample report shows as rows in a separate ancillary table. The second is that the page on the Fluid Reasoning Index, a sibling of this one, covers the other side of the same arrangement: Figure Weights is the subtest the two indexes share, so a reader who has both scores is looking at one subtest twice. The sibling page also covers the factor analytic debate about how many broad factors the Wechsler batteries really contain, and this page does not repeat it.

4 How is a QRI calculated and reported?

A QRI is reported as an index score with a percentile rank and a confidence interval, computed by adding the scaled scores of its two subtests and converting the sum through the publisher's norm tables. The conversion tables are the publisher's property and this page does not reproduce them. What a report shows is public. Pearson's WAIS-5 sample score report lists the QRI in its ancillary table with a sum of scaled scores, a composite score, a percentile rank, a 95 percent confidence interval, a qualitative description and a standard error of measurement. In that sample, Figure Weights and Arithmetic carry scaled scores of 10 and 9, the sum is 19, and the table gives a QRI of 98 at the 45th percentile with a confidence interval of 92 to 104 and the description Average (read October 29, 2026). It is a sample report published by the vendor, so the numbers show the format and nothing more.

The interval deserves a second look. It spans 12 points, which is our arithmetic on the printed bounds, and it says that the same person tested again could plausibly land anywhere in that band without having changed. A single point such as 98 hides this. The page on how IQ scores are normed explains how a raw score becomes a norm referenced score, and the page on reliability and validity explains why every score carries error. Every ACIS form reports the Full Scale IQ with a 95 percent confidence interval, and the technical manual documents the reliability and error of each index, so that this page does not need to restate them.

Why does a two subtest index lean on its interval so heavily? Because each subtest carries half of the weight. If one of the two tasks goes badly, through a lapse, a misheard item or a misread instruction, half of the index moves with it. The Standards for Educational and Psychological Testing (AERA, APA and NCME, 2014), open access on testingstandards.net, speak to this in Standard 2.3: for each total score, subscore or combination of scores that is to be interpreted, estimates of reliability and precision should be reported, and the comment adds that composites formed from selected subtests within a battery are frequently proposed for predictive and diagnostic purposes, so users need information about the reliability of such composites. For a QRI that means the reliability of the pair, not the reliability of the battery.

Finally, the two scores that make up the sum can differ widely and still produce a middling QRI. The same sum can come from two scaled scores of 10 or from a 14 and a 6. The index averages them away, which is one reason the ACIS manual asks the reader to compare the two subtests and not only to read the index.

5 How does a QRI differ from a math achievement score?

A QRI differs from a math achievement score in what its tasks reward: an achievement score reports what a person has been taught to do, while a quantitative reasoning index is meant to reward working out relations between quantities, although in practice most real indexes contain some of each. The CHC vocabulary draws the line, and the Riverside description of the WJ V cognitive battery draws it in a way that keeps the gradient visible. It defines mathematical achievement (A3) as measured mathematics achievement, including the ability to perform basic calculations and solve contextualized math problems, and then adds that both draw on quantitative reasoning, particularly as the achievement problems require more problem solving. A school mathematics test is therefore not free of reasoning, and a reasoning task is not free of schooling, a point the page on what a quantitative reasoning test measures develops from the CHC literature.

The practical difference is easiest to see in how a low score is explained. If a person scores low on an achievement test, the first explanations are instruction, practice and familiarity with notation. The ACIS page on the Mathematical Achievement subtest says as much: it describes the task as measuring acquired quantitative knowledge and the application of learned procedures, and it says a weaker result can reflect gaps in instruction, anxiety, speed, working memory or unfamiliar notation. By contrast, the ACIS page on the Figure Weights subtest describes a weaker result as possibly reflecting difficulty coordinating more than one relationship at a time and not necessarily weak mathematics.

Research on the overlap between reasoning and mathematics supports treating them as related and separable. Peng, Wang, Wang and Lin, in a 2019 meta-analysis in Psychological Bulletin, combined 680 studies with 793 independent samples and more than 370,000 participants. They found that fluid intelligence was moderately related to mathematics, r = .41, with a 95 percent confidence interval of .39 to .44, and moderately related to reading, r = .38. Squaring the mathematics coefficient gives about 17 percent shared variance, which is our arithmetic on their figure and is an average over many tasks, ages and samples that cannot describe one person. The authors also report that the relations were stronger for mathematics than for reading, stronger for complex skills than for foundational skills, and larger at older ages. The page on the relation between math ability and IQ takes that literature further, including what a correlation of that size leaves out.

Schooling matters for the achievement side, and it matters for the whole score. Ritchie and Tucker-Drob, in a 2018 meta-analysis in Psychological Science, combined quasiexperimental studies of education and intelligence, 142 effect sizes from 42 data sets with over 600,000 participants. They reported beneficial effects of education on cognitive abilities of approximately 1 to 5 IQ points for an additional year of education, effects that persisted across the life span and were present on all broad categories of cognitive ability studied. That finding is about education and cognitive scores in general, and it does not single out quantitative scores. It does mean that no index, including a QRI, is a pure measure of a fixed capacity.

The design of the pair decides how achievement loaded the index is. On the Wechsler scales, Pearson's WISC-V page says that when a child has intact language and computation and still scores low on Arithmetic, the cause may be quantitative reasoning, and that Figure Weights could provide more information. Pearson's answer points to Figure Weights as the subtest to consult for that explanation and treats Arithmetic as the mixed task. ACIS made a different choice, which the sections below set out: its pair has one school mathematics subtest and one mental calculation subtest, and it files Figure Weights under fluid reasoning. On our reading of the two sets of descriptions, the ACIS QRI is more achievement loaded than the Wechsler QRI, not less, and a reader should not assume that either one is the purer measure of reasoning. The page about math IQ tests separates where math ends and reasoning starts for readers who want the ability itself and not the index.

6 What abilities sit inside two quantitative subtests?

Two quantitative subtests carry at least four abilities between them, quantitative reasoning, learned calculation, working memory and language comprehension, and the weight of each depends on the task format. Pearson names these sources itself. In the WISC-V frequently asked questions it says that an examinee with significant language problems is likely to show lowered Arithmetic scores because of language comprehension, that an examinee with significant deficits in math operations will show low Arithmetic scores associated with that problem, that an examinee with intact language and computation may score low because of quantitative reasoning, and that an examinee with low working memory will score low because of problems manipulating information. It suggests Digit Span Backward, Digit Span Sequencing and Letter-Number Sequencing as ways to check the working memory explanation (page read October 29, 2026). A QRI averages that subtest with another.

The working memory load is the part readers tend to underrate. Pearson's WISC-V page describes Arithmetic as verbally presented, and ACIS delivers its own Arithmetic by sound as well: the examinee hears the problem and works it out in their head. The ACIS technical manual describes the task as a word problem delivered in the listening area, with no written copy left on screen, so that the terms must be held while the solution is computed and the format adds a retention demand to the arithmetic itself. The ACIS page on the Arithmetic subtest says the task is both quantitative and memory loaded, especially when problems must be solved without external working space, and the page on mental math tests goes through the memory load behind the sums. The sibling page on the Working Memory Index sets out how Arithmetic left that index between the two adult editions, which is the other side of the same puzzle.

Anxiety is the next documented influence. Ashcraft and Kirk, in a 2001 paper in the Journal of Experimental Psychology: General, reported that individuals with high math anxiety showed smaller working memory spans, especially when assessed with a computation based span task, and that this reduced capacity led to a pronounced increase in reaction time and errors when mental addition was performed together with a memory load. They described the effect as a transitory disruption of working memory. A later and much larger synthesis, the 2021 meta-analysis by Barroso and colleagues in Psychological Bulletin, analyzed 747 effect sizes from research between 1992 and 2018 and found a small to moderate negative correlation of r = -.28 between math anxiety and math achievement. A correlation of that size describes an average across many people. It does not show that anxiety lowers intelligence, and it does not say how much any one person's score moved on a given day. The page on taking an IQ test with no math also cites that meta-analysis, from the side of people who dread the subject.

7 What does the ACIS Quantitative Reasoning Index contain?

The ACIS Quantitative Reasoning Index contains exactly two subtests, Mathematical Achievement and Arithmetic, and the technical manual says the construct deliberately bridges quantitative knowledge and fluid reasoning. The manual, read October 29, 2026, describes the index as capturing quantitative reasoning, quantitative knowledge and learned numerical operations. The script that renders the ACIS report carries the same description: quantitative reasoning and mathematical achievement, a construct that bridges the two abilities. In reported score language the index sits beside the Verbal Comprehension, Fluid Reasoning, Visual Spatial, Working Memory and Processing Speed indices, and the Full Scale form reports all six. The table below sets out the two subtests as their ACIS pages and the manual describe them.

Three readings follow from the table. The first is that the two tasks lean on different resources. The manual calls Mathematical Achievement the most achievement oriented quantitative subtest in ACIS, a mixture of cognitive ability and learned academic exposure, and it says Arithmetic is less purely achievement based because it emphasizes active manipulation and efficient problem solving while still depending on learned number concepts. The manual adds that Arithmetic is sensitive to attention, anxiety, working memory and calculation fluency. The pair therefore covers a written style of problem solving with a reference sheet and a mental style of calculation with none.

The second reading is the manual's own rule for combining them. The manual says the QRI interpretation is strongest when Mathematical Achievement and Arithmetic converge. It then describes the two divergent cases. A low Arithmetic score with adequate Mathematical Achievement may indicate that the person understands mathematics but performs less efficiently under working memory demands, and a high Arithmetic score with lower Mathematical Achievement may indicate strong quantitative manipulation with narrower formal mathematics exposure. These are the manual's interpretive suggestions, which a reader should treat as hypotheses to check against the rest of the report, never as findings about a person.

The third reading is about forms. The QRI needs both subtests, and both are only in the Full Scale form, 50 dollars and about 175 minutes (prices read October 29, 2026, which can change), or in a Custom Test at 5 dollars per subtest, 10 dollars for the pair. The Quick form (15 dollars, about 45 minutes) and the Optimized form (30 dollars, about 110 minutes) contain neither subtest and do not report the index. The Custom Test description says any domain you complete returns its full index score, so the two quantitative subtests alone return a full QRI along with a scaled score for each subtest. A Custom Test does not return a Full Scale IQ, which needs the Full Scale battery, and at 10 subtests the Full Scale form costs the same. Someone who would rather avoid these subtests should know that the two lower priced forms leave them out, and the page on the Visual Number Series subtest describes a third quantitative task, filed under fluid reasoning in ACIS.

The manual lists one broader quantitative score. The Complete Quantitative Reasoning Index (CQRI) combines Mathematical Achievement, Figure Weights, Arithmetic and Visual Number Series, and the manual's description is that it expands quantitative reasoning beyond the two subtest QRI and adds quantitative pattern discovery. It is available when all four subtests are available, which the Full Scale form provides.

8 What can a QRI far from the other indices mean?

A QRI that sits far from the other indices can mean several different things at once, which is why the useful response is to look inside the index before looking outside it. The first step is to ask whether the gap is bigger than measurement error. The Standards for Educational and Psychological Testing (AERA, APA and NCME, 2014), in Standard 2.4, say that when the interpretation emphasizes differences between two observed scores of an individual, reliability and precision data, including standard errors, should be provided for those differences. The comment adds that psychodiagnostic inferences are frequently drawn from differences between subtest scores and that when the interpretation of test scores centers on the peaks and valleys in the examinee's profile, the reliability of score differences is critical. Standard 1.14 asks, in addition, that when interpretation of subscores, score differences or profiles is suggested, the rationale and evidence for that interpretation be provided.

The page on index score differences shows how often large gaps occur in people who have nothing wrong, and that is the base rate a reader needs before reading anything into a single gap. The caution is also in the research literature on profile interpretation. McGill, Dombrowski and Canivez, in a 2018 review in the Journal of School Psychology, describe cognitive profile analysis, which encourages practitioners to make diagnostic decisions or treatment recommendations from the strengths and weaknesses seen in ability score profiles, as a controversial aspect of intelligence testing, and they trace what they call new and continued concerns about it. Their review concerns school psychology practice, and it makes the same point as the Standards.

The second step is to look inside the index at its two subtests, because they can disagree. Pearson's WAIS-5 flyer says one use of its expanded index scores is to give more information when there is an unusual discrepancy between two subtests of a primary index, and a two subtest index is exactly where such a discrepancy matters most. In the ACIS version the manual's convergence rule applies: if Mathematical Achievement and Arithmetic point in different directions, the manual's suggestions are working memory efficiency in one direction and narrower formal mathematics exposure in the other.

The third step is to compare the QRI with its neighbors. A QRI below the other indices alongside a lower working memory index invites a look at the working memory side, as Pearson's own FAQ suggests. A QRI below a strong verbal index raises the question of schooling and language: the sibling page on the Verbal Comprehension Index covers how verbal scores are built, and the page on verbal versus quantitative ability shows how large a gap between the two sides has to be before it is worth discussing. A QRI below the fluid reasoning index suggests that learned procedures and not reasoning are the lower side, and on the Wechsler scales the two indexes share Figure Weights, so they are not independent. A QRI above the others can reflect schooling in mathematics, a calculation habit or interest, and a high score is no more diagnostic than a low one.

The fourth step is to look at the circumstances. The ACIS technical manual lists distraction, fatigue and motivation among the influences on speeded tasks in online testing, and audio conditions and attention among the influences on working memory tasks, and Arithmetic is both timed and heard. Background noise that masks the audio, or a dread of mathematics, can lower the pair for reasons that have nothing to do with the ability. A gap that does not reappear on a retest under better conditions should not be read as a stable difference.

What a QRI cannot do is diagnose. Pearson's WISC-V FAQ lists a math disability as one possible reason for low Arithmetic scores, next to language, quantitative reasoning and working memory, and it says the cause depends on the particular examinee and the relationship among measures, response processes and clinical information. Deciding which cause applies takes an evaluation by a qualified professional, and an unsupervised online index cannot make that decision. Group findings, such as the correlations above, describe averages across thousands of people and never a diagnosis for the reader. For readers whose interest in quantitative scores comes from selection testing, the sibling page on the military IQ test looks at one such battery.

9 Does the QRI add anything beyond the Full Scale IQ?

No source opened for this article shows that a QRI predicts anything beyond what the Full Scale IQ already predicts, and the nearest evidence, on the WAIS-IV index scores, says that index scores add little once the Full Scale IQ is known. That evidence needs careful labeling. Canivez, in a 2013 paper in Psychological Assessment, examined the incremental validity of the WAIS-IV factor index scores in predicting academic achievement on the Wechsler Individual Achievement Test (WIAT-II and WIAT-III) beyond the Full Scale IQ. The Full Scale IQ accounted for statistically significant and generally large portions of the variance in the achievement scores. The factor index scores together provided statistically significant increments in most cases, with effect sizes from trivial to medium, and individually they provided trivial to small unique contributions. Canivez concluded that the Full Scale IQ should retain primacy and the greatest interpretive weight.

The labeling is the important part. The WAIS-IV indexes in that study are four factor indexes, and none of them is a QRI, which is newer and ancillary. The finding is therefore an analogy for how index scores behave in a Wechsler battery, and it is not a result about the QRI. We did not find, in the sources opened for this page, a study of the QRI's own incremental validity, and the claim on Pearson's WAIS-5 product page that the new index is a predictor of academic and career success stays a publisher's claim until a study is read. This is not a reason to ignore the index, since a score can describe something useful without predicting an outcome better than another score. It is a reason to ask what question the index is being used to answer.

The overlap between the QRI and the Full Scale IQ also matters. On the WISC-V, Pearson says the Full Scale IQ is based on seven subtests, and Figure Weights is one of them, so the QRI and the Full Scale IQ share a subtest. A reader who sees a QRI above or below the Full Scale IQ is comparing a score with a larger score that contains half of itself, and the page on the General Ability Index compares that composite with the Full Scale IQ. Pearson's WAIS-5 flyer lists the subtests of its General Ability Index as Similarities, Vocabulary, Block Design, Matrix Reasoning and Figure Weights, so Figure Weights sits in the GAI too, and Arithmetic sits in neither. The ACIS technical manual describes its own GAI as a composite across verbal, fluid, visual spatial and quantitative reasoning, which shows again that the same composite name can describe different subtest sets.

The practical reading is a modest one. In the one study reviewed here the Full Scale IQ kept the greatest interpretive weight, and the QRI is a lens for examining one part of a profile. The ACIS manual warns against the mirror image of over-reading an index, which is using the Full Scale IQ alone while ignoring a clearly uneven profile. Both mistakes are available, and the Standards' requirement of evidence for score differences and profiles applies to both.

10 Where can you get a quantitative reasoning index score?

A QRI score comes from two kinds of source, a psychologist who selects it from a Wechsler battery and a normed online battery that reports its own quantitative index, because a math quiz or a job screening practice test does not return an index. The table compares the real options as of October 29, 2026. Where a cell says not stated, the page read does not say.

A few cautions go with the table. Pearson's instruments are restricted: the WAIS-5 and WISC-V product pages list qualification level C, so the first two rows are professional services, not products a member of the public can buy. The page on where to take an IQ test lists every route, in person and online, and the page on the best online IQ tests compares normed online options.

For adults whose purpose is personal, the page on IQ testing for adults describes the ACIS route and the free trial, and the page on cognitive ability tests covers the broader family of tests that report ability scores. None of these routes substitutes for a professional evaluation when the purpose is clinical, educational or legal.

11 What does an unsupervised session need for the quantitative subtests?

The two ACIS quantitative subtests need working sound, a quiet room and, for Mathematical Achievement, pen and scratch paper, and they are best taken rested because the audio and the clock are part of the task. Arithmetic presents its items as audio and needs working sound, which is the main technical requirement of the pair. The Arithmetic page says to wait until the audio finishes before responding, and the second section lets the examinee replay each item once, but the timer keeps running, so a replay costs seconds out of the 30 allowed for the item. The page also states that no external aids are allowed, which excludes calculators, notes, scratch paper and drawing tools. A person who uses scratch paper on Arithmetic has changed the task into a different one, and the working memory load the manual describes is reduced.

Mathematical Achievement is the opposite. Its page allows pen and scratch paper, forbids calculators and offers a reference table of formulas that can be opened and closed, and the manual says the table means the subtest measures the application of mathematical procedure and not formula recall. The page states a total limit of 35 minutes for 25 questions, one point per correct answer and no penalty for wrong answers, and the manual notes that an explicit option to say the answer is not known keeps omissions distinguishable from errors.

Three conditions cut across both subtests. The first is the room. The technical manual lists distraction, fatigue and motivation among the influences on speeded tasks in online testing, and audio conditions and attention among the influences on working memory tasks, which means a score reflects the conditions it was taken in. The second is breaks: the ACIS forms allow breaks, progress is saved between subtests, and a purchase gives 30 days to finish, so the two quantitative subtests do not have to be taken at the end of a long afternoon. The third is honesty about the format. Nobody watches an online session, which is why the manual describes security controls without detailing them, and why the score assumes the person followed the stated rules. Arithmetic carries a 30 second limit per item, so response speed can matter alongside accuracy.

The reading load deserves a final word. Arithmetic is a word problem heard in English, and the manual says verbal and knowledge tasks are affected by English proficiency and educational exposure. A person who learned mathematics in another language, or who has a hearing difficulty that headphones do not fix, should expect the score to say something about those conditions as well as about quantitative ability.

12 Where ACIS sits, and what a buyer should do

ACIS sells assessments, so this section is a disclosure: ACIS reports a Quantitative Reasoning Index as a primary index, from two subtests, in an online unsupervised session, and that fits it to describing one adult profile, not to replacing a clinical evaluation. The strengths are concrete. The index is reported on the standard scale with a percentile and a confidence interval, the two subtests have their own pages, and the Custom Test lets a buyer pay 10 dollars for the pair instead of 50 dollars for all 20 subtests (prices read October 29, 2026, and they can change). The Full Scale form adds the other five indices and the CQRI, and the technical manual documents how each score was built. The page on the technical manual is the place to check that documentation, and this page deliberately quotes none of its statistics.

The limits are equally concrete. ACIS is online and unsupervised, and it is not a clinical or diagnostic instrument. It is not for hiring decisions, school accommodations or admission to high IQ societies, and its tasks are in English only. A two subtest QRI is coarse, so a gap from the other indices is a prompt, as the previous sections show, and not a finding. A QRI from ACIS cannot be compared with a Pearson QRI: the subtest pairs differ, the norm groups differ, and nothing on this page claims equivalence.

The Standards for Educational and Psychological Testing (AERA, APA and NCME, 2014) say what a reader should ask of any such score. Standard 2.3 asks for reliability and precision information for every score that is to be interpreted, including combinations of subtests, and Standard 2.4 asks for it for any difference between two scores that is to be emphasized. Standard 1.14 asks for a rationale and evidence when subscores, differences or profiles are interpreted. The APA's Guidelines for Psychological Assessment and Evaluation (2020) ask psychologists to select tools with sufficient validity evidence and score reliability (Guideline 6), and to be aware of the limitations of measures and of the context that can affect results. They are written for psychologists, and the same logic carries over to the person reading a report: the score is one piece of evidence, with error and with context, and not a trait stamped on a person.

What should a buyer do? Start with the purpose. If the purpose is official, such as a documented accommodation, a diagnosis or a legal question, the route is a qualified psychologist. If the purpose is personal, such as understanding the quantitative side of a profile, a Custom Test with Mathematical Achievement and Arithmetic returns a QRI for 10 dollars, and the Full Scale form returns it with every other index. Read the example report first, take the subtests when rested with sound working, and read the index beside the other indices and the interval, never alone. If a gap appears, compare the two subtests, then the neighboring indices, then the circumstances, and treat a repeat under better conditions as the real test of the gap. The guarantee on the site reads: "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."

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. Pearson pages and ACIS pages were read on October 29, 2026. Where this page does arithmetic on a published figure, it says so, and the page does not attribute any derived number to an author.

• American Educational Research Association, American Psychological Association and National Council on Measurement in Education. Standards for Educational and Psychological Testing. AERA, 2014. Standards 1.14, 2.3 and 2.4.
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• Ashcraft M, Kirk E. The relationships among working memory, math anxiety, and performance. Journal of Experimental Psychology: General, 2001, volume 130, issue 2, pages 224 to 237.
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• Canivez G. Incremental criterion validity of WAIS-IV factor index scores: Relationships with WIAT-II and WIAT-III subtest and composite scores. Psychological Assessment, 2013, volume 25, issue 2, pages 484 to 495.
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• Pearson Assessments. Wechsler Intelligence Scale for Children, Fifth Edition (WISC-V) product page and frequently asked questions. Read October 29, 2026.
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• Pearson Assessments. A guide to WAIS-5 ancillary index scores, flyer C10536 EL 9/24, 2024. Read October 29, 2026.
• Pearson Assessments. WAIS-5 overview brochure. Read October 29, 2026.
• Pearson Assessments. WAIS-5 sample score report, report dated September 16, 2024. Read October 29, 2026.
• Pearson Assessments. WAIS-IV sample score report. Read October 29, 2026.
• Riverside Insights. Woodcock-Johnson V Tests of Cognitive Abilities, descriptions of the CHC broad and narrow abilities. Read October 29, 2026.

14 Frequently Asked Questions