A letter number sequencing test that adds sorting to span

0 The short answer

The Letter-Number Sequencing test is a spoken working memory task in which you hear a mixed series of letters and numbers and say it back reordered, numbers first in ascending order and then letters in alphabetical order, so it measures holding plus sorting where plain forward digit span measures holding almost alone. It began as the letter-number span that Gold and colleagues introduced in 1997, it is a supplemental subtest of the WAIS-IV and a secondary subtest of the WAIS-5, and a psychologist gives it in person. An adult who wants a normed online version of the same task family can take ACIS Alphanumeric Sequencing, which is in the Quick form (15 dollars, about 45 minutes, prices read October 29, 2026) and in the free trial of the Full Scale form. The decisive limit is that it is one short subtest taken online without a supervisor, so it describes your performance on that task and is not a clinical result.

1 What is the Letter-Number Sequencing test?

Letter-Number Sequencing is a task in which you hear letters and numbers in a scrambled order and must report them back in a fixed order, which forces you to hold the series and rearrange it at the same time. The wording of the rule is stable across the sources opened for this page. Pearson's page for the WAIS-IV (read October 29, 2026) says the examinee repeats the numbers in ascending order first and then the letters in alphabetical order. A 2018 paper in Applied Cognitive Psychology by Mielicki, Koppel, Valencia and Wiley describes the same task as hearing a series of letters and digits and reporting back the stimuli with the letters in alphabetical order and the digits in ascending numerical order, and calls it a working memory capacity measure included in the WAIS-III and WAIS-IV batteries.

The task has a research origin that is separate from the Wechsler batteries. Gold, Carpenter, Randolph, Goldberg and Weinberger examined 30 healthy participants and 36 patients with schizophrenia in Archives of General Psychiatry (1997) on a neuropsychological battery that included what they called a novel measure of working memory, letter-number span. Their question was clinical, whether a working memory deficit contributes to performance on the Wisconsin Card Sorting Test in schizophrenia, and this page draws no clinical conclusion from it. What matters for a reader who searched for the test is the date and the label. Later research treats the two as the same family of task: Bruder and colleagues describe a letter-number test and cite both the 1997 paper and the WAIS-III for it. This page reports that shared name and format and does not claim to know how the Wechsler publisher developed its own version.

To make the format concrete without reproducing any test item, here is one short illustration written for this page and not taken from any test. If you heard the five characters 9, R, 2, M, 5, the ordered answer would be 2, 5, 9, M, R: the numbers sorted from smallest to largest, then the letters in alphabetical order. Real items vary in length and in how the letters and numbers are interleaved, and the sources opened for this page describe formats and not content. Nothing here is a practice set.

Three features drive everything that follows. The material is presented once, aloud, at a steady pace, so a listener cannot reread it. The answer has two parts under two separate rules, so the listener must classify each character as a letter or a number while it arrives. And the correct order is not the heard order, so replaying what you heard fails even when every character was remembered. The sibling page on the Working Memory Index shows how batteries combine tasks of this kind into one index, and the page on the short term memory test covers the storage-only end of the range.

2 Where does Letter-Number Sequencing appear in the Wechsler batteries?

Letter-Number Sequencing has moved from a contributor to the Working Memory Index in the WAIS-III and the WISC-IV to an optional extra in the WAIS-IV, the WAIS-5 and the WISC-V, and that change is the reason the same name appears with different weights in different reports. The table sets out what the sources opened for this page say, with the publisher pages read on October 29, 2026.

For the WAIS-III, Hill and colleagues state in the Journal of Clinical and Experimental Neuropsychology (2010) that the Working Memory Index is derived from performance on the Digit Span, Arithmetic and Letter-Number Sequencing subtests. They add that the subtest has high face validity as a working memory task and that, unlike Digit Span, it appears to require more than immediate memory.

For the WAIS-IV, Pearson's WAIS-IV vs. WAIS-5 comparison flyer, lists Comprehension, Figure Weights, Picture Completion, Letter-Number Sequencing and Cancellation as the supplemental subtests, and lists Digit Span and Arithmetic among the ten core subtests. The Pearson WAIS-IV product page answers a question that explains the demotion. It states that Arithmetic was chosen over Letter-Number Sequencing as a core subtest and that the introduction of Digit Span Sequencing decreased the unique information that Letter-Number Sequencing contributes to the battery. The same page asks why Letter-Number Sequencing, Figure Weights and Cancellation are not administered to ages 70 to 90, which tells a reader that the subtest is not part of every adult administration. The page on the WAIS-IV and its index scores goes through the full subtest list.

For the WAIS-5, the same flyer sorts the subtests into primary and secondary tiers. The primary list includes Digit Sequencing and Running Digits, and the secondary list includes Digits Forward, Digits Backward and Letter-Number Sequencing, among others. The page on the 20 WAIS-5 subtests lists the whole battery, and the sibling page on the Working Memory Index explains the ancillary working memory indexes into which the secondary subtests feed.

For the child batteries, the Pearson WISC-V page says Picture Span, a new visual working memory subtest, replaced Letter-Number Sequencing in the Working Memory Index, which had contributed to the WISC-IV version, and that Digit Span is the only subtest the two versions share. A reader who searched for the WISC version should know that the WISC-V covers children from 6:0 to 16:11 and that an adult takes a WAIS battery instead.

Two practical points follow. A report that says the task was administered does not mean it entered the Full Scale IQ, because the WAIS-IV Full Scale IQ is built from the 10 core subtests and the WAIS-5 flyer counts 7 subtests in its Full Scale IQ, and the task is listed in neither the WAIS-IV core tier nor the WAIS-5 primary tier. And because the task is supplemental or secondary, many adult Wechsler reports will not contain it at all, which is an ordinary outcome and not an omission.

3 What does Letter-Number Sequencing add to plain digit span?

Letter-Number Sequencing adds a rearrangement of two classes of material under two ordering rules, and the research shows that this addition is real but modest, because digit span explains much of the variance in the task. Start with what digit span asks. In forward digit span you hear digits and repeat them in the order heard. The demand is storage and serial order, which the page on the Digit Span subtest describes as immediate auditory-verbal storage and, in harder versions, active manipulation of ordered material. Reversing the digits or putting them in ascending order, as the WAIS-IV and the ACIS subtest do, already adds manipulation. So the honest comparison is not between a storage task and a manipulation task. It is between a digit task that has several conditions and a task in which the manipulation is built into every item and the material has two types.

The most direct evidence comes from Crowe (2000) in Assessment, who asked whether the task measures anything more than digit span. A total of 102 undergraduate students performed the task alongside measures of reading, working memory, motor execution, visuospatial memory and executive functions. Performance on the task was uniquely predicted by reading level, forward and backward digit span, arithmetic, visual spatial learning and the WAIS-III Symbol Search subtest. Crowe concluded that much of the variance on the task is explained by the traditional digit span measures, and that additional unique contributions come from processing speed and visual spatial working memory. The accurate reading of that abstract is two-sided. The task is not a copy of digit span, because speed and visual spatial measures predicted it independently. It is also not a different universe, because digit span accounted for much of what it measured.

Hill and colleagues (2010) reached a compatible position from the opposite direction. They evaluated the WAIS-III against a working memory criterion construct and reported that Letter-Number Sequencing appears to require more than immediate memory, that Digit Span explained more variance on its own than Letter-Number Sequencing did, and that both subtests were retained in the best-fitting model. A reader should take from this that the two subtests are partly redundant and partly complementary, which fits a battery that includes both.

Egeland (2015), writing in Applied Neuropsychology: Adult, asked whether the extended WAIS-IV versions of Digit Span and Letter-Number Sequencing contribute enough complexity to be sensitive measures of manipulation. In a mixed sample of 226 patients referred for neuropsychological examination, a model that separated auditory tasks from the visual Spatial Span task fit best, and the paper advises clinicians to use tests with higher manipulation load and to consider testing visual span as well. The title says the manipulation load is too low. That is a cautious finding about a clinical referral sample and not a verdict on healthy adults, but it is a reminder that sorting a heard series into two ordered groups is a modest manipulation, and not the heavy load of a complex span task that interleaves a separate processing job.

The broader review literature explains why the contrasts are graded. Unsworth and Engle (2007), in Psychological Bulletin, reviewed simple and complex span tasks and concluded that they largely measure the same basic subcomponent processes, such as rehearsal, maintenance, updating and controlled search, but differ in the extent to which each process operates in a particular task. Under that account, Letter-Number Sequencing sits between a pure forward span and a complex span. It recruits more updating and control than forward repetition, because the listener must classify and reorder, and it does not interleave a second activity the way counting span or operation span does. The sibling pages on the auditory memory test and on the short term memory test cover the storage end and the definitional debate.

The technical manual for ACIS states the same logic in its description of Alphanumeric Sequencing. It describes a series that must be held while two ordering rules are applied, says the subtest separates adequate retention from efficiency once sorting and dual rule control are added, and in its glossary says it adds executive reordering beyond simple storage. The word adds is the one that matters: the task is built on storage and then asks for more, which fits Crowe's finding that digit span underlies it. The broader topic is covered by the page on working memory tests for adults.

4 How is the Letter-Number Sequencing test scored?

Letter-Number Sequencing is scored trial by trial, with each trial worth 0 or 1 point and three trials making up an item, and the raw total becomes meaningful only after it is compared with an age-based reference group. The best open description of the WAIS-IV structure comes from an item response theory study by Abdelhamid, Bassiouni and Gomez-Benito in the International Journal of Environmental Research and Public Health (2021). They list Letter-Number Sequencing as a 10 item subtest that assesses working memory and define the item score as the total score of its three trials, each corrected with 0 or 1 point. An item therefore scores from 0 to 3. If the raw score is the sum of the item scores, as that structure suggests, the largest possible raw total would be 30, which is our arithmetic on the published structure and not a figure the paper states.

The rules for starting and stopping are in the NIH data dictionary entry for the WAIS-IV subtest, in the Federal Interagency Traumatic Brain Injury Research Informatics System (FITBIR, read October 29, 2026). It says administration starts with a demonstration item, a sample item and then Item 1, and that the examiner discontinues after scores of 0 on all three trials of an item. It also records a prompt for the first two items: if the examinee does not say the number first, the examiner reminds the examinee to say the number first and then the letter. Those details show that the task teaches the rule before it counts anything, stops when an item is failed completely, and treats the order of the answer as the whole point.

The Wechsler structure is not the only way to score the format. In the research literature the scoring unit is often simpler. Bruder and colleagues, in the Journal of Abnormal Psychology (2011), describe a letter-number working memory test in which strings of intermingled letters and numbers are presented aloud and the participant stores and reorders them, reciting the numbers in numeric order and the letters in alphabetical order. Their dependent measure is the total number of correct strings, and the paper cites both Gold and colleagues (1997) and the WAIS-III for the test. The lesson for a reader is that "the letter number sequencing score" is not one thing. A count of correct strings in a research paper and an item score built from three trials in a clinical battery are different quantities, and neither is comparable to a number from an app that defines its own points.

The raw total does not travel by itself. A raw score of a given size means something different at 25 than at 65, and the same raw score from two tests of different lengths means different things. That is why batteries convert raw scores into scaled scores using norms for an age group. ACIS reports subtest results as scaled scores from 1 to 19, with a mean of 10 and a standard deviation of 3, and its indices and Full Scale IQ on the familiar scale with a mean of 100 and a standard deviation of 15. Percentiles and a 95 percent confidence interval accompany them, and adult norms cover ages 16 to 90. The page on how IQ scores are normed explains the logic of comparing a person with a reference group of the same age. The public Digit Span page makes the age point for span tasks: absolute performance on span and speed tasks falls across adulthood while standing within a birth cohort stays stable, so a raw span only becomes interpretable against an age reference group.

On the ACIS side, the public Alphanumeric Sequencing page states that it does not disclose protected item content, scoring keys, adaptive rules or administration details, so this page does not report the number of items or the stopping rule, and it records both as not stated. What the page does show is the completion screen, which lists the time taken, the raw score and the scaled score. The practical reading is the same as for any norm-referenced subtest: the scaled score is the number to carry away, and the raw score is a step on the way to it.

5 Which cognitive abilities does the task measure?

The task samples working memory capacity, with auditory short term storage beneath it, and its link to fluid reasoning is strong at the level of the construct but is not an identity. In the Cattell-Horn-Carroll (CHC) model that ACIS uses, the broad ability is Gwm, working memory. The public Alphanumeric Sequencing page places the task in working memory or short-term memory capacity (Gwm/Gsm) and says performance can depend on attention control, sequencing, resistance to interference and the format of the material. The technical manual lists the narrow abilities of the ACIS subtest as working memory capacity and auditory short term storage. Pearson's WAIS-IV page, for its part, lists Letter-Number Sequencing in a CHC mapping under short term memory, with Digit Span and Arithmetic. The page on the CHC model lists the broad and narrow abilities.

Crowe's predictors add detail. Reading level and arithmetic predicted performance alongside the two digit span measures, which fits the structure of the task: a listener must know the alphabet well enough to order letters, must handle numbers fluently, and must do both while holding the series. This page's reading is that the task needs a basic fluency with letters and numbers to be a clean test of working memory, so a listener with an unusual relation to the English alphabet is at a disadvantage that has nothing to do with capacity. The next section returns to that. Crowe also found that the WAIS-III Symbol Search subtest predicted performance, and that processing speed and visual spatial working memory made unique contributions beyond digit span. The sibling page on the Digit Symbol Substitution Test covers a classic speed measure, and the page on the processing speed test covers the speed index in a normed battery.

How does working memory relate to reasoning? Kane, Hambrick and Conway wrote in Psychological Bulletin (2005) that working memory capacity is not isomorphic with general fluid intelligence or reasoning ability, but that the two constructs are more strongly associated than a competing paper indicated. Their reanalysis of 14 latent-variable data sets from 10 published studies, representing more than 3,100 young adults, found a median correlation of .72 between working memory capacity and fluid reasoning factors, which they said indicates that the constructs share approximately 50 percent of their variance. Two cautions apply to a reader who has a single sorting task in mind. The result is about constructs measured with several tasks, not about one subtest, and a correlation of that size leaves about half the variance in each construct unshared. So someone who scores high on a letter and number task is not thereby shown to reason well, and someone who scores low is not shown to reason poorly. The page on what IQ measures shows how the domains relate to a general factor.

The ACIS technical manual is cautious in the same way. It treats working memory as one of six domains, describes the pattern of an adequate Digit Span with a weaker Alphanumeric Sequencing as a possible difficulty reorganizing information under rules, and uses the word may. The page on IQ and memory places these results in the wider question of how memory and intelligence relate, including the common myths.

The manual also lists a composite, the Cognitive Proficiency Index, that combines working memory and processing speed as cognitive proficiency. Alphanumeric Sequencing is one of its subtests. The sibling page on the Cognitive Proficiency Index explains how that composite is built across batteries and why a gap between it and a general ability composite proves little by itself.

6 How do modality, language and age change performance?

Performance on the task depends on whether the material is heard or seen, on the examinee's relation to the language and the alphabet, and on age, so a raw result should always be read against matched adults. Start with modality. The Mielicki group's paper is titled for the advantages of visual administration, and its abstract says the task is traditionally administered orally while recent studies have displayed the stimuli on a computer screen. The authors tested whether the modality of administration affects performance and report that performance differences on the task may arise as a function of language background and task administration modality. Egeland's study of the WAIS-IV makes a related point from a clinical direction: the WAIS-IV tests only the auditory modality, and the analysis found that a model that separated modalities fit the data best. For a reader the practical consequence is that a spoken version and an on-screen version are not interchangeable, and a norm built on one does not automatically apply to the other.

Language background is the second factor. The task asks for letters in alphabetical order, so it assumes a known alphabet and a comfortable relation to the language in which the letters are named. An examinee who learned the alphabet in another language, or who hears letter names in an unfamiliar accent, may be doing extra work. The ACIS technical manual states that verbal and knowledge tasks are affected by English proficiency and educational exposure, and the Alphanumeric Sequencing subtest is presented in English as audio. The whole ACIS test is available in English only. This is one reason to read a working memory result beside the other results in a profile and not as a stand-alone verdict.

Age is the third factor. Emery, Myerson and Hale reported two experiments in Psychology and Aging (2007) on age differences in working memory tasks involving complex item manipulation, with the letter-number task as the case. In their first experiment, age differences on manipulation tasks were not greater than on tasks requiring recall of items in the order in which they appeared, which they took to suggest that older adults do not have difficulty with item manipulation as such. In the second, slower presentation rates increased age differences in item manipulation spans, although differences at the fastest rate may reflect strategy use. In both experiments, age differences were largest when participants were most likely to be remembering familiar sequences, which led them to suggest that older adults may have difficulty dampening the representations of such sequences once they are activated. These are group findings from two laboratory experiments, and they say nothing definite about one person. They do show that the age pattern in this task is not a simple story of manipulation failing, and that the pace of presentation matters.

7 Which letter number sequencing test options exist for an adult?

An adult meets this task through a psychologist's WAIS administration, through free demonstrations of uncertain provenance, or through a normed online battery such as ACIS, and the options differ most in who the score is compared with and who watched you take it. The table compares them. Prices and times come from pages opened on October 29, 2026 and can change, and a cell says "not stated" when the source is silent.

A psychologist is the right route when the question is clinical or when a decision needs a supervised, individually administered result, and the page on where to take an IQ test compares in-person and online routes. The page on the WAIS test online explains what official online options exist and where they stop. The comparison above has one catch that is easy to miss: a reader who wants the Letter-Number Sequencing score specifically may not get it, because the task is optional in the adult batteries.

Free demonstrations deserve a plain description. A search for the exact phrase on October 29, 2026 returned research task libraries, a simple browser version of the task, school worksheets on number and letter patterns, and verbal reasoning quizzes about series. The worksheets and quizzes are pattern puzzles, which is a different thing from holding and reordering a heard string. A free demonstration of the real task is a fact about that demonstration, and the question to ask is what its scores are meant to mean and for which population. The page on the free IQ test explains how to judge free offers, and the page on the best online IQ tests compares the paid options with their prices.

ACIS is one concrete option and not the only one, and it sells the product described in the table, so weigh that disclosure as you read. Job screening practice tests belong in a different category, because they familiarize a candidate with a format and are not IQ tests. A reader who wants a brief published scale rather than a working memory subtest can read the sibling page on the Shipley-2 test. The next section describes the ACIS task in detail.

8 What is the ACIS Alphanumeric Sequencing subtest?

ACIS Alphanumeric Sequencing belongs to the same task family as Letter-Number Sequencing, delivered as audio with the numbers first from smallest to largest and then the letters in alphabetical order, and it is the sorting end of the ACIS working memory domain. The public Alphanumeric Sequencing page describes tasks that ask a person to hold a mixed stream of letters and numbers, separate the two classes and then reorder each class according to a rule. It says the task requires updating, organization and controlled mental rearrangement, and that it is read beside digit span because it can show a person who retains material adequately but becomes less efficient once sorting, sequencing or dual-rule control is added. This is the ACIS version of the format and not the Wechsler subtest, and nothing on this page implies that the two are equal or interchangeable.

The page also shows what a session looks like. The examinee plays the instructions audio and then presses Begin. The numbers and letters play at one per second. A practice screen is marked as not scored. A later section raises the sequence length, and the examinee is told to keep listening until the sequence ends before typing a response, with the reminder that the answer is numbers first from smallest to largest and then letters in alphabetical order. No external aids are allowed, which the page spells out as calculators, notes, scratch paper and drawing tools. The format therefore matches the one in the research and clinical literature, with one difference worth stating: the page states a pace of one character per second and does not mention any way to slow the presentation down.

The technical manual places the subtest in the working memory domain beside Digit Span and Visual Sequence. It describes the subtest as reflecting working memory capacity and auditory short term storage, and as representing active auditory verbal working memory rather than passive storage alone. The pattern reading it offers is the one this page has used throughout: if Digit Span is adequate but Alphanumeric Sequencing is weaker, the person may maintain information but have difficulty reorganizing it under rules, and if both are strong, the auditory working memory profile is more robust. The word the manual uses is may, and a reader should keep it. The manual defines the Auditory Working Memory Index composite as built from Digit Span and Alphanumeric Sequencing, and says that although both subtests appear in the Quick and Optimized forms, the composite is reported only on the Full Scale form. The page on the Digit Span subtest covers the forward, backward and sequencing conditions, and Visual Sequence is the visual counterpart in the same domain.

The access facts, read on October 29, 2026, are these. The free trial of the Full Scale form opens five subtests, Digit Span, Alphanumeric Sequencing, Visual Sequence, Coding and Symbol Search, with no card, one trial per person, and finished trial subtests are kept if the person later unlocks a form that includes them. Quick costs 15 dollars, has 6 subtests and takes about 45 minutes, as detailed on the page about the Quick IQ test. Optimized costs 30 dollars, has 13 subtests and takes about 110 minutes. Full Scale costs 50 dollars, has all 20 subtests and takes about 175 minutes. All three include Alphanumeric Sequencing. The Custom Test costs 5 dollars per subtest and returns each subtest's scaled score. Every payment is one time, breaks are allowed, progress is saved between subtests, and a purchased form can be completed within 30 days. Prices can change.

9 How do you read a Letter-Number Sequencing score?

Read an Alphanumeric Sequencing result as a scaled score with a band around it, compare it with the Digit Span result inside the same profile, and treat a gap between the two as a question and not a finding. The scaled score runs from 1 to 19 with a mean of 10 and a standard deviation of 3, so a score of 7 or 13 sits one standard deviation from the mean, which on a normal curve is roughly the 16th or 84th percentile. The page on IQ scores versus percentiles explains why the two scales should not be averaged or confused, and a percentile table converts one into the other.

Precision is the second layer. The Standards for Educational and Psychological Testing (AERA, APA and NCME, 2014), 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. Its comment adds that it is not sufficient to report reliability and standard errors only for total scores when subscores are also interpreted, and that composites formed from subtests within a battery need their own reliability information. A single subtest is a subscore, and it is usually less precise than the battery total built from many. As a general illustration only, and not an ACIS figure, suppose a hypothetical subtest score has a standard error of about 1.5 scaled points. A 95 percent band is then about plus or minus 3 points (1.96 times 1.5 is 2.9, our arithmetic), so an observed 10 would be consistent with a true standing from about 7 to 13. That band is wider than most readers expect, and it is the reason a one point difference between two subtests is rarely a finding. The page on reliability and validity explains these terms with examples.

Differences deserve extra care, and they are the usual reason people compare Letter-Number Sequencing with Digit Span. Standard 2.4 says that when an interpretation emphasizes differences between two observed scores of an individual, reliability and precision data, including standard errors, should be provided for such differences. Its comment notes that when interpretation centers on the peaks and valleys of a profile, the reliability of score differences is critical. In the same hypothetical illustration, the standard error of a difference between two independent scores would be the square root of 2 times 1.5, about 2.1 scaled points (our arithmetic), so a gap between a digit result and a letter and number result must be large before it says anything. The page on index score differences shows how often sizable gaps occur in ordinary profiles, a useful corrective to reading every gap as a strength or a weakness.

One more habit helps. The public Digit Span page notes that a weaker span result may reflect distraction, anxiety, sequencing difficulty or limits in active manipulation, and the same list applies here, so a low score invites a question about the session before it invites a conclusion about the person.

10 How should you set up an unsupervised session?

An unsupervised audio task measures what the room lets it measure, so settle the sound, the quiet and the rules before the first item. The ACIS Digit Span and Alphanumeric Sequencing subtests present their items as audio and need working sound. The Digit Span page advises headphones or a quiet space, and the Alphanumeric Sequencing page asks the examinee to play the instructions audio first. Silence notifications on the phone and the computer, close other tabs that can make sound, and choose a time when no one will speak to you. A task in which characters arrive once, one per second, has no recovery from an interruption: a second voice in the room during an item changes what the item measures.

Do not write the characters down, record them or use any other aid. The page says no external aids are allowed, and writing the series as it plays would turn a working memory task into a transcription task. The instruction to keep listening until the sequence ends before typing matters for the same reason: typing while characters are still playing would split attention between new input and the stored series. If hearing is a concern, that is a conversation to have with a professional and not something to settle by interpreting a score.

The Standards speak to this setting directly. Standard 6.4 says the testing environment should furnish reasonable comfort with minimal distractions to avoid construct-irrelevant variance, and its comment names noise, disruption in the testing area and malfunctioning computers as conditions to avoid, adding that technology-based administrations should avoid distractions such as equipment or Internet-connectivity failures. Standard 6.3 asks that changes or disruptions to standardized administration be documented and reported, and its comment says testing environments that are not monitored, such as those on the Internet, should meet standardized administration conditions, and that otherwise the report on scores should note that standardized conditions were not guaranteed. The APA Guidelines for Psychological Assessment and Evaluation (2020), Guideline 8, ask psychologists to be aware of the need for test selection, scoring and administration to reflect the appropriate normative comparison, situational influences, effort and standardized administration. A clinician controls those. An online test taker has to control them personally, and an honest note that a session was disrupted is a reason to give the score less weight.

ACIS allows breaks and saves progress between subtests. Take the working memory subtests when you are alert, take any break between subtests and not in the middle of one, and avoid an audio subtest late in a long session.

11 What can a Letter-Number Sequencing score not tell you?

A Letter-Number Sequencing result describes how you performed on a structured listening and sorting task, and it cannot diagnose anything, predict everyday forgetting or stand in for a full evaluation. The research origin of the task is clinical, since Gold and colleagues introduced it in a study that compared healthy participants with patients with schizophrenia, and Egeland's analysis used patients referred for neuropsychological examination. Those are research and clinical samples, and the findings describe averages across groups of people. Group statistics are never individual diagnoses. This page does not use the task to say anything about any condition, and ACIS does not claim to detect memory impairment, attention difficulties or any other condition.

If the reason you searched for the test is a concern about concentration, memory or a change that you or others have noticed, the right step is to talk to a doctor or a licensed psychologist, who can examine the whole picture and use instruments designed and supervised for that purpose. A normal online score would not rule anything out, and a low one would not rule anything in. The same restraint applies upward. A high scaled score on one working memory subtest is one result on one task and is not a measure of overall intelligence, a gifted identification or a high-range IQ. The page on the high range IQ test addresses that question with the right instrument.

12 Where ACIS sits, and what a buyer should do

ACIS is one commercial option for a normed version of this task, it is sold by the publisher of this page, and its limits are as important as its features: it is online, unsupervised, not clinical and available in English only. The Standards for Educational and Psychological Testing (AERA, APA and NCME, 2014) bear on how any score from this page should be read. Standard 1.1 says the test developer should set forth clearly how test scores are intended to be interpreted and used, delimit the population and describe the construct, and its comment says it is incorrect to use the unqualified phrase "the validity of the test," because each recommended interpretation for a given use requires validation. Standard 2.3 asks for reliability and precision estimates for each score that is interpreted, and Standard 2.4 asks for them for differences between scores. Standard 6.10 asks that interpretations describe in simple language what the test covers, what scores represent and the precision of the scores. Standard 6.3, in its comment, says unmonitored testing should either meet standardized conditions or note that they were not guaranteed.

The APA guidance adds two points that apply directly. Guideline 6 of the APA Guidelines for Psychological Assessment and Evaluation (2020) asks psychologists to select assessment tools that demonstrate sufficient validity evidence for their uses and sufficient score reliability, and Guideline 8 asks for attention to the appropriate normative comparison, situational influences, effort and standardized administration. For a buyer those mean three things: read the interval and not the point, read the subtest pages for what each task samples, and read the technical manual for the documentation before leaning on any score. ACIS is not designed for hiring decisions, school accommodations or admission to high IQ societies, and it does not diagnose. The guarantee is worded exactly as follows: "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."

Here is what to do. If your question is clinical, or a decision depends on the result, start with a licensed psychologist, and ask whether Letter-Number Sequencing is part of the battery, since it is optional in the adult Wechsler batteries. If you want to see how your auditory sorting compares with adults, and whether it is a strength or a valley in your own profile, the free trial of the Full Scale form is the lowest cost way to take Alphanumeric Sequencing together with Digit Span and Visual Sequence. If you want a broader picture, the page on the IQ test for adults is the entry point to the whole battery. Use a quiet room and headphones, avoid notes, and treat the first score as an observation to confirm and not a finding to act on.

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. The calculations labeled as our arithmetic (the 30 point maximum, the 95 percent band and the standard error of a difference) are our own arithmetic on published structure or on a hypothetical value, and the illustration of the task is original to this page. Publisher pages and prices were read on October 29, 2026 and can change.

• American Educational Research Association, American Psychological Association and National Council on Measurement in Education. Standards for Educational and Psychological Testing. Washington, DC: AERA, 2014 (Standards 1.1, 2.3, 2.4, 6.3, 6.4 and 6.10).
• American Psychological Association, APA Task Force on Psychological Assessment and Evaluation Guidelines. APA Guidelines for Psychological Assessment and Evaluation. Approved by the APA Council of Representatives, March 2020 (Guidelines 6 and 8).
• Abdelhamid G, Bassiouni M and Gomez-Benito J. Assessing Cognitive Abilities Using the WAIS-IV: An Item Response Theory Approach. International Journal of Environmental Research and Public Health, 2021, volume 18, issue 13, article 6835.
• Bruder G, Alschuler D, Kroppmann C, Fekri S, Gil R, Jarskog L, Harkavy-Friedman J, Goetz R, Kayser J and Wexler B. Heterogeneity of auditory verbal working memory in schizophrenia. Journal of Abnormal Psychology, 2011, volume 120, issue 1, pages 88 to 97.
• Crowe S. Does the Letter Number Sequencing Task Measure Anything More Than Digit Span? Assessment, 2000, volume 7, issue 2, pages 113 to 117.
• Egeland J. Measuring Working Memory With Digit Span and the Letter-Number Sequencing Subtests From the WAIS-IV: Too Low Manipulation Load and Risk for Underestimating Modality Effects. Applied Neuropsychology: Adult, 2015, volume 22, issue 6, pages 445 to 451.
• Emery L, Myerson J and Hale S. Age differences in item manipulation span: The case of letter-number sequencing. Psychology and Aging, 2007, volume 22, issue 1, pages 75 to 83.
• Federal Interagency Traumatic Brain Injury Research Informatics System. WAIS-IV Letter-Number Sequencing, Item, Trial response text (data dictionary entry). National Institutes of Health. Read October 29, 2026.
• Gold J, Carpenter C, Randolph C, Goldberg T and Weinberger D. Auditory Working Memory and Wisconsin Card Sorting Test Performance in Schizophrenia. Archives of General Psychiatry, 1997, volume 54, issue 2, pages 159 to 165.
• Hill B, Elliott E, Shelton J, Pella R, O'Jile J and Gouvier W. Can we improve the clinical assessment of working memory? An evaluation of the Wechsler Adult Intelligence Scale, Third Edition using a working memory criterion construct. Journal of Clinical and Experimental Neuropsychology, 2010, volume 32, issue 3, pages 315 to 323.
• Kane M, Hambrick D and Conway A. Working Memory Capacity and Fluid Intelligence Are Strongly Related Constructs: Comment on Ackerman, Beier, and Boyle (2005). Psychological Bulletin, 2005, volume 131, issue 1, pages 66 to 71.
• Mielicki M, Koppel R, Valencia G and Wiley J. Measuring working memory capacity with the letter-number sequencing task: Advantages of visual administration. Applied Cognitive Psychology, 2018, volume 32, issue 6, pages 805 to 814.
• Pearson Assessments. Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV) product page. Read October 29, 2026.
• Pearson Assessments. WAIS-IV vs. WAIS-5 comparison flyer (comparison flyer, document code CE1013 EL 5/24). Read October 29, 2026.
• Pearson Assessments. Wechsler Intelligence Scale for Children, Fifth Edition (WISC-V) product page. Read October 29, 2026.
• Unsworth N and Engle R. On the division of short-term and working memory: An examination of simple and complex span and their relation to higher order abilities. Psychological Bulletin, 2007, volume 133, issue 6, pages 1038 to 1066.

14 Frequently Asked Questions