A short term memory test that separates holding from working

0 The short answer

A short term memory test measures how much you can hold in mind for a few seconds, and the decisive distinction is that working memory adds a second job: using what you hold. Repeating a sequence in the order you heard it is the cleaner short term task, while reversing or sorting it is a working memory task, and the research shows the line between them is graded rather than sharp, with a capacity of about four chunks according to Cowan's review, not the seven of popular memory. ACIS offers three span subtests, Digit Span, Alphanumeric Sequencing and Visual Sequence, in the free trial of the Full Scale form, and the Quick form (15 dollars, about 45 minutes, prices read October 29, 2026) includes the first two. The decisive limit is that an online, unsupervised, non clinical score describes span performance on those tasks and cannot tell you whether you have a memory problem.

1 What is the difference between short term memory and working memory?

Short term memory is holding information for a brief interval, working memory is holding it while doing something with it, and the literature uses both words in more than one way. Nelson Cowan, in a review of the three kinds of memory in Progress in Brain Research (2008), opens by noting considerable confusion about long term, short term and working memory. He proposes that short term memory differs from long term memory in two ways, temporal decay and a limit on the number of chunks, and says both properties remain controversial, although the current literature is encouraging about each. The same chapter lists three definitions of working memory: short term memory applied to cognitive tasks, a multicomponent system that holds and manipulates information in short term memory, and the use of attention to manage short term memory.

The second definition fits a test that asks you to hold something and then reorder it. Alan Baddeley's account of the multicomponent approach in the Annual Review of Psychology (2012) describes a theoretical framework that has remained relatively stable, with more specific models built inside it. For a test taker the practical reading is simple. If a task asks you to say back what you heard, in order, storage does most of the work. If it asks you to reverse, sort or update what you heard, storage is still needed, and a control process is added on top of it.

The ACIS technical manual draws the same line in its description of Digit Span. The examinee reproduces digit sequences under three conditions: in the order presented, in reverse order, and re-ordered into ascending sequence. In the manual's account, holding the material is common to all three, but reversal and re-ordering add manipulation on top of storage. The conditions therefore differ in how much working memory capacity they demand beyond short term storage, even though the digits are the same. The technical manual is where those definitions are set out in full.

In the Cattell-Horn-Carroll (CHC) model that ACIS uses, the broad ability is called Gwm, working memory. The manual defines it as the capacity to maintain and manipulate information over short intervals under attentional control, and it lists narrow abilities beneath it, among them working memory capacity, auditory short term storage and visual spatial short term storage. The public Digit Span page writes the domain as Gwm/Gsm, which shows how closely the two ideas travel inside the framework. The page on the CHC model lists the broad and narrow abilities, and the page on cognitive domains shows where working memory sits among the six domains ACIS reports.

Everyday speech uses the phrase differently. People who search for a short term memory test are often thinking of remembering what happened this morning or where the keys went, which belongs to a different part of the memory system than a span task does. A span task samples what you can keep active for seconds, usually with the material presented once. That is a narrow slice of memory, and the page on how IQ and memory relate places it among the other memory processes. The rest of this page deals only with that slice, and the page on working memory testing in general owns the broader topic.

2 What do short term memory test examples look like?

Short term memory tests use a small set of recurring formats, and the useful question about each is how much it asks you to do with the material besides hold it. Describing formats is different from showing items, and this page does not reproduce any item from any real test. The formats below are the ones documented in the sources opened for this page.

The first three rows are the Digit Span conditions that Pearson lists for the WAIS-5 as Digits Forward, Digit Sequencing and Digits Backward (the Pearson WAIS-5 page, read October 29, 2026), and Gignac and Weiss analyzed three Digit Span indicators in the WAIS-IV normative sample in Psychological Assessment (2015). The fourth and fifth rows are the formats of the ACIS Alphanumeric Sequencing and Visual Sequence subtests as their public pages describe them: numbers and letters play at one per second and the answer is numbers first, from smallest to largest, then letters in alphabetical order; and for tiles, the examinee clicks them in the order they flashed, then in reverse. The sixth row names the complex span family. Conway and colleagues describe counting span, operation span and reading span as widely used measures of working memory capacity in their methodological review in Psychonomic Bulletin and Review (2005), and Cowan's chapter describes such tasks as those that include both storage and processing components.

Two further points help when comparing examples. First, the modality is part of the format: digits that are heard load a phonological route, while tiles that flash load a spatial one, and the manual notes that auditory and visual working memory are related but not identical. The sibling page on the auditory memory test covers the heard side in depth, and the visual side has its own page. Second, a task can look like a memory test while mostly measuring something else. A recall game that rewards a clever strategy, a chunking trick or a familiar word is sampling more than span, which is the point of the next section.

3 How do span tasks measure each kind of memory?

Simple span tasks ask for storage and complex span tasks add a processing demand, and a major review of the evidence finds that the two overlap substantially. Unsworth and Engle, in a review in Psychological Bulletin (2007), start from the claim that short term memory and working memory, as measured by simple and complex span tasks, are separate constructs differentially related to higher order abilities. They then evaluate that claim against experimental and correlational studies, and with a meta-analysis and re-analyses of key data sets. Their conclusion is that simple and complex span tasks 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.

They add that the differences depend largely on two features: how far phonological processes are maximized, and whether long list lengths introduce variability. That finding has a practical consequence for anyone choosing a test. On that account a forward digit task leans on phonological maintenance, while a backward or sequencing version, or a letter and number task, recruits more updating and control. Neither is a pure measure of one process, and a test that claims to isolate short term memory from working memory with a single task is claiming more than this review supports.

The earlier claim was a separation. Engle, Tuholski, Laughlin and Conway ran a study in which 133 participants performed 11 memory tasks, some thought to reflect working memory and some short term memory, plus two tests of general fluid intelligence and the Verbal and Quantitative Scholastic Aptitude Tests (Journal of Experimental Psychology: General, 1999). Structural equation modeling suggested that short term and working memory reflect separate but highly related constructs, and that many of the tasks used as working memory tasks reflect a common construct. The two papers are best read together. The 1999 result established that the distinction is worth making. The 2007 review showed that the distinction depends on task design, which reads as a difference of degree.

The ACIS manual's descriptions fit that graded reading. It says Digit Span reflects working memory capacity plus auditory short term storage, reads Alphanumeric Sequencing beside it, and describes Visual Sequence as the visual counterpart. A three subtest domain therefore lets a reader see how performance changes as the demand on control rises and as the material changes from heard to seen, which is a different goal from drawing a line between two kinds of memory.

Complex span tasks have their own measurement logic. Conway and colleagues, in the user's guide cited above, address the reliability and validity of the tasks and the technical aspects of administration and scoring, and they discuss latent variable analysis and extreme-groups designs as the statistical techniques commonly used with them. Latent variable analysis combines several tasks into one shared factor, which is the logic behind reading a battery of tasks instead of a single score, and the same caution applies to a single subtest in any battery.

4 How many items can short term memory hold?

Short term memory holds about four chunks when rehearsal and regrouping are controlled, and the seven that most people remember was a rough estimate rather than a measured limit. George Miller's 1956 paper, The magical number seven, plus or minus two in Psychological Review, is the source of the figure. Cowan's target article in Behavioral and Brain Sciences (2001) summarizes the history: Miller summarized evidence that people can remember about seven chunks, but that number was meant more as a rough estimate and a rhetorical device than as a real capacity limit. Others later suggested a more precise limit of only three to five chunks, and Cowan's article brings together a wide variety of data supporting the smaller limit.

The key word is chunk. A chunk is a unit that the person treats as one item, so a familiar word can count as one chunk although it contains many letters. Cowan names four conditions in which capacity can be observed because chunks can be identified: when information overload limits chunks to individual stimulus items, when other steps block recoding of items into larger chunks, in performance discontinuities caused by the capacity limit, and in indirect effects of the limit. Under those conditions rehearsal and long term memory cannot be used to combine items into chunks of unknown size. The result is a single central limit averaging about four chunks.

The later summaries agree. In The Magical Mystery Four in Current Directions in Psychological Science (2010), Cowan contrasts Miller's seven chunks of meaningful items with findings that young adults recall only about three or four longer verbal chunks, and he argues for a central store limited to 3 to 5 meaningful items in young adults. He adds that mathematical models of working memory settle on a value of about four. His 2008 chapter says the limit in capacity is more typically only three or four units, and elsewhere in the same chapter gives a wider range of about two to six items in adults, which is a reminder that the estimate carries uncertainty and varies with the procedure.

What does that mean for a test taker whose span on a digit task is longer than four? Cowan's account implies that a longer digit span reflects more than the central store. Recoding digits into groups, rehearsing them and drawing on long term memory can all raise the number of digits reported without raising the number of chunks held. That does not make the score uninformative. A digit span is a performance measure under standard conditions, and what it ranks is how well a person combines storage with the strategies the format allows. It does mean that a raw span of seven should never be read as seven items of capacity, and that a score becomes meaningful only against adults who took the same task in the same way. The section on reading scores below returns to that point.

Duration is the other property Cowan assigns to short term memory, and it is the more contested one. He calls temporal decay tentative and debated, and cites a study in which the delay before the test mattered within the first 5 seconds. For an unsupervised test the practical lesson is about conditions rather than theory: because the material is held for seconds and is easily displaced, an interruption, a glance away or a second voice in the room changes what is being measured. The section on taking a test at home covers that.

Two nearby topics have their own pages. Popular accounts of a photographic or unlimited visual store are evaluated in the page on photographic memory and what science supports, and the visual side of the capacity limit, including the sequence tasks used to measure it, is covered in the page on why four items is the limit in visual memory. The auditory side is the subject of a sibling page. This page keeps to the holding versus working distinction that those three pages assume.

5 How do short term memory and working memory relate to fluid intelligence?

Working memory is strongly related to fluid reasoning and simple short term span is related less strongly, but how large the gap is depends on how much control a task recruits, and the relation is an association, not an identity. The original latent variable study by Engle and colleagues found that working memory shows a strong connection to fluid intelligence but short term memory does not. Cowan's 2008 chapter says the same from another angle: measures of working memory have been found to correlate with intellectual aptitudes, while the simple serial recall tasks usually identified with short term memory do not correlate as highly in adults. The same chapter notes an exception, since a simple digit span served as an excellent correlate of aptitude in children too young for covert verbal rehearsal.

How strong is the working memory link? Kane, Hambrick and Conway wrote a comment in Psychological Bulletin (2005) on a paper by Ackerman, Beier and Boyle that they said understated the association. They agreed that working memory capacity is not isomorphic with general fluid intelligence, and they reanalyzed 14 data sets from 10 published studies, with more than 3,100 young adults in all. The median correlation between working memory and fluid reasoning factors was 0.72, which they describe as indicating that the two constructs share approximately 50 percent of their variance. A correlation of that size is strong, and it also means that about half of the variance in each construct is unshared, so two people with the same working memory score can differ in reasoning and the reverse.

Simple span is not irrelevant to general intelligence, either. Wechsler contended in 1958 that beyond an average level of Digit Span there was little benefit to a greater memory span. Gignac and Weiss tested that contention in the WAIS-IV normative sample (1,800 people, ages 16 to 69) and found that all three Digit Span indicators showed primarily linear associations with the Full Scale IQ and general intelligence, so the commonly held position was not supported. The title of their paper puts it directly: every extra bit of span counts. The three indicators include conditions that add manipulation, so the result does not isolate pure holding, and it is consistent with the other findings above.

Unsworth and Engle's 2007 review explains why the picture can look inconsistent. If simple and complex span tasks share most of their subprocesses and differ in degree, then whether a particular simple task correlates with reasoning depends on how much control it recruits. Which of the two a given simple task resembles depends, on that account, on features such as how far phonological processes are maximized and how long the lists are. The technical manual takes a cautious position on the whole question. It says Digit Span should be interpreted as a working memory measure, not as a measure of reasoning, that it can influence performance on more complex tasks because many tasks require temporary storage, and that it is not identical to fluid reasoning. A low Digit Span with strong reasoning, the manual says, may show a profile where reasoning is better than raw serial storage. The page on fluid intelligence testing covers the reasoning side, and the page on what IQ measures shows how the domains relate to a general factor.

The way a battery uses this relation is visible in its composites. The manual describes the General Ability Index as a composite that reduces dependence on working memory and processing speed, and the Cognitive Proficiency Index as one that combines working memory and processing speed. A reader who has strong reasoning and a lower span can therefore see that pattern in two different summaries, and the page on the General Ability Index compares that composite with the Full Scale IQ.

6 Which short term memory test should you take?

The right test depends on whether you want a clinician's observation, a quick game result or a normed score you can read against adults, and the options differ most in what they are normed against. The table compares the real choices for an adult. Prices and times come from pages opened on October 29, 2026 and can change. A search for the topic on that date returned many pages framed around memory loss screening and online memory games, which is a different purpose from the one this page addresses.

The Pearson WAIS-5 page lists Digits Forward, Digit Sequencing, Digits Backward and Running Digits among the subtests and describes Running Digits as a new auditory working memory subtest whose recalibration items are meant to discourage rehearsal. It says Digits Forward is a secondary subtest that does not contribute to the Full Scale IQ or primary indexes. The Full Scale IQ uses 7 subtests in about 45 minutes, and the age range is 16:0 to 90:11. The page states nothing about prices or the logistics of a session, so those cells say so rather than guess. A clinician is the right route when the question is clinical, a point the later section on limits makes in more detail, and the page on where to take an IQ test compares in person and online routes.

Free games deserve a plain description rather than a verdict. Many are entertaining, and a score from one is a fact about that game. The question to ask of any page is who the score is compared with, and whether it separates holding from working. 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. It has two features this page considers relevant. It reports span against adult norms rather than as a bare count, and the same three subtests sit inside a wider battery, so you can see whether a span result is a peak or a valley in your own profile. Its limits are the usual ones for an online test: no examiner is present, the test is not clinical, and it is available in English only. The page on the cognitive ability test frames the wider battery as a measure of cognitive ability, and the page on the IQ test for adults is the entry page for adults who want the whole battery.

7 How do you read a short term memory score?

A span score is meaningful only against an age reference group, and the useful numbers are the scaled score or index with its confidence interval, not the count of items you repeated. The public Digit Span page makes the point plainly: 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. The page on how IQ scores are normed explains the logic of comparing a person with a reference group of the same age.

ACIS reports subtest results as scaled scores from 1 to 19, with a mean of 10 and a standard deviation of 3, and indices and the 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. The page on why the standard deviation of 15 matters shows why those two scales line up, and a scaled score of 7 or 13 sits one standard deviation from the mean, which is roughly the 16th or 84th percentile. The page on IQ scores versus percentiles explains why the two should not be averaged or treated as the same thing, and the IQ percentile calculator 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, asks that estimates of reliability and precision be reported for each total score, subscore or combination of scores that is interpreted, and its comment adds that composites formed from subtests within a battery need their own reliability information. 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 is a band wider than most readers expect from a single number, 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. Standard 2.4 asks that when an interpretation emphasizes the difference between two observed scores of an individual, reliability and precision data, including standard errors, be provided for that difference, and 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 is the square root of 2 times 1.5, about 2.1 scaled points (our arithmetic), so a gap between a forward and a backward result needs to be large before it says anything. The page on index score differences shows how often sizable gaps occur in ordinary profiles, which is a useful corrective to reading every gap as a strength or a weakness.

The manual offers pattern readings as hypotheses and not as verdicts. If Digit Span is adequate but Alphanumeric Sequencing is weaker, the manual says the person may maintain information but have difficulty reorganizing it under rules. A high Visual Sequence score with a lower Digit Span may suggest stronger visual than auditory working memory. The word the manual uses is "may", and the sensible reading follows it: treat a pattern as a question worth a second look, and treat a single session as one observation.

8 How does age change span performance?

Span performance falls across adulthood on average while verbal knowledge rises, which is why a span score needs an age reference group. Park and colleagues studied 345 adults across the life span in Psychology and Aging (2002). They report that beginning in the 20s a continuous, regular decline occurs for processing intensive tasks such as speed of processing, working memory and long term memory, whereas verbal knowledge increases across the life span. They also find that visuospatial and verbal working memory are distinct but highly interrelated systems with domain specific short term memory subsystems, which fits a battery that offers both heard and seen span tasks.

These are group averages, and a group average says nothing definite about one person. A raw span that is shorter at 60 than at 25 is the expected pattern on average, and it is not by itself a sign of a problem. The score that carries meaning is the comparison with adults of the same age, and that comparison is what a normed test supplies. The page on the IQ test for adults over 40 takes up what changes and what holds in the middle decades, and the page on working memory testing covers the adult years for working memory in more depth. Anyone who is worried about changes in everyday memory should speak to a clinician, because a span test is not designed to answer that question and a normal score would not settle it.

9 How do you take a span test at home?

An unsupervised span test measures what the room lets it measure, so set up the sound, the quiet and the rules before the first item. The ACIS pages for Digit Span and Alphanumeric Sequencing present their items as audio and say that numbers and letters play at one per second. The Digit Span page advises headphones or a quiet space, and both audio subtests need working sound. Visual Sequence is different: it shows tiles that flash, and the examinee clicks them in order. All three pages say that no external aids are allowed, which means no calculator, notes, scratch paper or drawing tools. Writing digits down, even briefly, turns a memory task into a transcription task, and the pages rule it out.

The instruction on the audio pages is to keep listening until the sequence ends before typing a response. It matters because typing while digits are still playing would split attention between the new digits and the stored ones. 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. The arithmetic subtest in the same battery is also presented as audio, and the sibling page on the mental math test covers the quantitative side of that format.

The Standards speak to this setting directly. Standard 6.3 asks that changes or disruptions to standardized administration be documented and reported to the test user, and its comment adds that testing environments that are not monitored, such as those on the Internet, should meet the 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, Guideline 8, ask psychologists to be aware of situational influences, effort and standardized administration. A clinician controls those. An online test taker has to control them personally, and an honest report of a disrupted session is a reason to retake a subtest rather than to trust a doubtful score.

ACIS allows breaks and saves progress between subtests, and a purchased form can be completed within 30 days. Use that flexibility: take the span subtests when you are alert, because effort is one of the situational influences the guidance above asks to be considered, and take any break between subtests and not in the middle of one.

10 What do the three ACIS span subtests measure?

The three ACIS span subtests cover heard digits, heard letters and numbers with a sorting rule, and seen tile sequences, so together they show whether storage, control or modality is driving a result. Each has its own public page. On the Digit Span page, the task has three sections. In the first the examinee repeats digits in the order heard, in the second in reverse, and in the third enters the digits remembered from smallest to largest. The manual states the same conditions as in the order presented, in reverse order and re-ordered into ascending sequence, and it classes the subtest as an auditory working memory indicator that samples the ability to hold and reproduce sequences under controlled conditions.

The Alphanumeric Sequencing page describes a mixed stream of letters and numbers that the examinee must separate and reorder: numbers first from smallest to largest, then letters in alphabetical order. Because two classes and two rules are held at once, the manual says the subtest separates adequate retention from efficiency once sorting and dual rule control are added. That is the working memory end of the range. The Visual Sequence page describes tiles that flash in an order that the examinee reproduces, first forward and then in reverse. The manual calls it the visual counterpart to Digit Span and says its defining operation is temporary storage and controlled sequence reproduction, even though the material is visual. It belongs to the working memory index and not to the visual spatial index as a primary score.

For readers who want to compare a seen sequence with a spatial skill, the manual notes that a low Visual Sequence score with adequate visual spatial reasoning may suggest that the difficulty lies in maintaining the sequence and not in visual processing itself. The clinical counterpart on the spatial side is a construction task: the Pearson WAIS-5 page lists Block Design among its subtests, and the sibling page on the block design test covers that family, which is usually filed under visual spatial ability and not under memory.

The manual also defines predefined composites that use these subtests. It describes AWMI as focusing on auditory working memory through Digit Span and Alphanumeric Sequencing, VWMI as built on Visual Sequence alone (so a single indicator that calls for caution), and CPI as combining working memory and processing speed as cognitive proficiency. The processing speed side of that composite is the subject of the page on the processing speed test. The technical manual lists every composite and its subtests.

On cost and access, the facts read on October 29, 2026 are these. The free trial of the Full Scale form opens five subtests, among them Digit Span, Alphanumeric Sequencing and Visual Sequence, with no card, and finished trial subtests are kept if the person later unlocks a form that includes them. Quick (15 dollars, 6 subtests, about 45 minutes) includes Digit Span and Alphanumeric Sequencing. Optimized (30 dollars, 13 subtests, about 110 minutes) includes the same two. Full Scale (50 dollars, 20 subtests, about 175 minutes) is the only one of the three forms that includes Visual Sequence. The Custom Test costs 5 dollars per subtest, so the three working memory subtests together cost 15 dollars, and it returns each subtest's scaled score and the full index for any domain that is completed. Every form is a one time payment with no subscription. The refund wording is exact: "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." Prices can change.

11 What can a short term memory score not tell you?

A span score describes performance on a structured task and cannot tell you about everyday forgetting, a memory disorder or how well you learn new material. Cowan's chapter separates short term memory from long term memory by decay and chunk limits, which already marks the boundary: remembering a telephone number for a few seconds and recalling something learned last week draw on different kinds of memory. A span score belongs to the first, and the public Digit Span page says that a weaker result may reflect distraction, anxiety, sequencing difficulty or limits in active manipulation. It also says that digit span tasks are rarely read as a knowledge measure, which is useful for readers who worry that a score reflects schooling.

This is not a clinical instrument, and ACIS does not claim to detect memory impairment or any condition. Group statistics are never individual diagnoses: the findings in this page, from the 0.72 correlation to the age trends, describe averages across samples of people. If your concern is the kind that prompted the search in the first place, such as forgetting recent conversations, losing track of things more often than before, or a change that others have noticed, the right step is to talk to a doctor or a licensed psychologist, who can examine the whole picture and use tests that are meant 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 to the other direction. A high span is one result on one task and should not be read as evidence of a "photographic" store. As the section on intelligence showed, span is related to reasoning without being the same thing, and the raw span in digits depends on strategies that the format allows. The overview page on memory and IQ includes a section on common myths about IQ and memory.

Finally, a short test is a short sample. One subtest of a few minutes cannot represent the construct, which is why batteries use several tasks and why the manual says a profile is read as a pattern. The practical use of a span result is to see where it sits in a wider profile and to compare it informally with your own experience of holding and using information at work or study, without treating either as proof of the other. The six domains ACIS reports are the frame for reading any single result.

12 Where ACIS sits, and what a buyer should do

ACIS is one commercial option for a normed span score, 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 asks the developer to set out how scores are intended to be interpreted and used, to delimit the population and to 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, Standard 2.4 asks for them for differences between scores, and 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 Guidelines for Psychological Assessment and Evaluation (2020) add three points that apply directly. Guideline 6 asks psychologists to select tools with sufficient validity evidence for their uses and sufficient score reliability. Guideline 7 asks for multiple sources of relevant and reliable information. 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.

Here is what to do. If your question is clinical, start with a clinician. If you want to see how your span compares with adults, and whether your result 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 the three span subtests. If you want only the working memory domain, the Custom Test at 5 dollars per subtest returns it for 15 dollars across the three subtests, while Quick at 15 dollars also includes four other subtests. 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 two small calculations in the section on reading scores (the 95 percent band and the standard error of a difference) are our own arithmetic on a hypothetical value and are labeled as such. Prices and product details 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 and 6.10).
• American Psychological Association, 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, 7 and 8).
• Ackerman P, Beier M and Boyle M. Working Memory and Intelligence: The Same or Different Constructs? Psychological Bulletin, 2005, volume 131, issue 1, pages 30 to 60.
• Baddeley A. Working Memory: Theories, Models, and Controversies. Annual Review of Psychology, 2012, volume 63, pages 1 to 29.
• Conway A, Kane M, Bunting M, Hambrick D, Wilhelm O and Engle R. Working memory span tasks: A methodological review and user's guide. Psychonomic Bulletin and Review, 2005, volume 12, issue 5, pages 769 to 786.
• Cowan N. The magical number 4 in short-term memory: A reconsideration of mental storage capacity. Behavioral and Brain Sciences, 2001, volume 24, issue 1, pages 87 to 114.
• Cowan N. What are the differences between long-term, short-term, and working memory? Progress in Brain Research, 2008, volume 169, pages 323 to 338.
• Cowan N. The Magical Mystery Four. Current Directions in Psychological Science, 2010, volume 19, issue 1, pages 51 to 57.
• Engle R, Tuholski S, Laughlin J and Conway A. Working memory, short-term memory, and general fluid intelligence: A latent-variable approach. Journal of Experimental Psychology: General, 1999, volume 128, issue 3, pages 309 to 331.
• Gignac G and Weiss L. Digit Span is (mostly) related linearly to general intelligence: Every extra bit of span counts. Psychological Assessment, 2015, volume 27, issue 4, pages 1312 to 1323.
• 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.
• Miller G. The magical number seven, plus or minus two: Some limits on our capacity for processing information. Psychological Review, 1956, volume 63, issue 2, pages 81 to 97.
• Park D, Lautenschlager G, Hedden T, Davidson N, Smith A and Smith P. Models of visuospatial and verbal memory across the adult life span. Psychology and Aging, 2002, volume 17, issue 2, pages 299 to 320.
• Pearson Assessments. Wechsler Adult Intelligence Scale, Fifth Edition (WAIS-5) 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