Working Memory
Running Span
Also called: running memory span, running digit span, running span task, running memory task
Measure working memory capacity with lists that stop without warning: digits appear one at a time, and participants recall the last 3 to 7 in order.
9-11 minUntimed
Free to start: 10 free participants per account, then $0.99 per participant for academic research, or any yearly plan. Preview any test free after you sign up.
- Papers, 2021 to 2025
- 17
- Evidence grade
- C
- Registered clinical studies
- 5
What it measures
Measures working memory capacity with lists that stop without warning. Digits appear one at a time, and when a list stops, participants enter its last 3 to 7 digits in order.
Constructs
- Working memory capacity
- Working memory updating
- Serial order memory
Research uses
- Working memory research in aging and clinical groups
- Individual-differences studies of working memory and fluid intelligence
- Within-study comparison of fast and slow presentation
How the paradigm works
The Running Span measures working memory capacity with lists that stop without warning. Digits appear one at a time at the center of the screen, each for 300 ms, one every 2,000 ms. When a list stops, the participant enters its last few digits in the order they appeared, by typing or on an on-screen keypad. Because the end cannot be predicted, the digits to report are not known until the list stops.
More about the paradigm
The task follows the running memory span of Pollack, Johnson and Knaff (1959) as Broadway and Engle (2010) gave it: one part for each number of items to report, named before the part begins, each with one list that stops right after those items and one each that runs on by 1, 2 or 3 extra items before them, in a random order; items shown for 300 ms at one item every 500 ms or every 2,000 ms; and strict serial scoring of the items to report. Here the items are the digits 1 to 9, which read the same in every language, where theirs were letters. Parts ask for the last 3 to 7 digits by default, 20 lists in a random order of parts (3 to 8 digits in their first experiment, a setting), after two practice lists with feedback. The pace is set before the session, from 500 to 2,500 ms (standard 2,000), and never changes during it.
No digit comes back within nine neighbors, so the digits to report are all different, and no three digits count up or down by one. Broadway and Engle let participants click a blank for an item they could not recall; here every place needs a digit, so the entry screen asks for a best guess. Scores are best compared within studies and at the same pace.
The main score is the running span score: digits entered in their place among the digits to report, on the lists that ran on past them (0 to 75 at the standard settings). As in Broadway and Engle, lists that stop right after the digits to report are left out of it, because they need no updating; they are scored on their own. The share of digits in place, the share for each number of digits and the lists recalled in full are also given. Broadway and Engle found recall higher at the slow pace than at the fast one, with the same links to complex span tasks and fluid intelligence at both. Scores support research and do not diagnose.
Scores
- Running Span Scorecount
- Digits entered in their place among the digits to report, on the lists that ran on past them. 0 to 75 at the standard settings.
- Higher is better
- Digits in Place%
- The running span score over the digits to report on those lists.
- Higher is better
- Last 3 Digits%
- Share of digits in place on lists that asked for the last 3 and ran on.
- Higher is better
- Last 4 Digits%
- Share of digits in place on lists that asked for the last 4 and ran on.
- Higher is better
- Last 5 Digits%
- Share of digits in place on lists that asked for the last 5 and ran on.
- Higher is better
- Last 6 Digits%
- Share of digits in place on lists that asked for the last 6 and ran on.
- Higher is better
- Last 7 Digits%
- Share of digits in place on lists that asked for the last 7 and ran on. Null when the most digits to recall is set to 6.
- Higher is better
- Last 8 Digits%
- Share of digits in place on lists that asked for the last 8 and ran on. Null unless the most digits to recall is set to 8.
- Higher is better
- Whole Lists%
- Share of digits in place on lists that stopped right after the digits to report, which need no updating.
- Higher is better
- Lists Fully Recalledcount
- Lists that ran on with every digit to report entered in its place.
- Higher is better
- Median Entry Timems
- Median time from the recall screen to Submit.
- Informational
- Lists Completedtrials
- Test lists recorded in the scored run.
- Under 90% of the planned lists is invalid
- Planned Liststrials
- Test lists the session planned to give.
- Informational
Use and evidence
17 papers from 2021 to 2025 name this task in their title or abstract, down 41% compared with 2016 to 2020. That ranks it 342 of 395 test families in our census. See the counts for every test.
Show the numbers
| Year | Papers |
|---|---|
| 2025 | 8 |
| 2024 | 3 |
| 2023 | 2 |
| 2022 | 2 |
| 2021 | 2 |
| 2020 | 1 |
| 2019 | 7 |
| 2018 | 7 |
| 2017 | 7 |
| 2016 | 7 |
| 2015 | 5 |
| 2014 | 4 |
| 2013 | 3 |
| 2012 | 4 |
| 2011 | 1 |
| 2010 | 5 |
| 2009 | 0 |
| 2008 | 4 |
| 2007 | 2 |
| 2006 | 2 |
| 2005 | 1 |
| 2004 | 0 |
| 2003 | 1 |
| 2002 | 0 |
| 2001 | 3 |
| 2000 | 0 |
Use grade E
Fewer than 30 papers from 2021 to 2025.
Evidence grade C
At least 2 test-retest papers, 30 reliability or validity papers or 3 registered clinical studies.
- Papers on test-retest reliability
- 1
- Papers on reliability or validity
- 5
- Registered clinical studies using it as an outcome
- 5
How the grades work
Use: A is 1,000 or more papers from 2021 to 2025, B 300 to 999, C 100 to 299, D 30 to 99 and E fewer than 30. Evidence: A means at least 25 papers report its test-retest reliability and at least 25 registered clinical studies use it as an outcome; B, at least 8 test-retest papers, and either 5 registered clinical studies or 150 reliability or validity papers; C, at least 2 test-retest papers, 30 reliability or validity papers or 3 registered clinical studies; D, little published measurement evidence found. The counts measure use. They include every paper that names the task in its title or abstract. Grades describe the published research on this task, not ConductCognition's version of it.
Source: ConductCognition test census 0.14.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
Task design
The trial sequence as the test runs in ConductCognition.
- Digits
- 1 to 9, one at a time at the center, each for 300 ms, one every 2,000 ms (standard; 500 to 2,500 ms as a setting, fixed for the session).
- Parts
- One for each number of digits to recall, the last 3 up to the last 7 (standard; up to 6 or 8 as a setting), in a seeded order, each named before it starts.
- Lists
- Four in each part, in a seeded order: one stops right after the digits to recall, and three run on by 1, 2 or 3 extra digits before them. 20 lists in all at the standard settings.
- List rules
- No digit comes back within nine neighbors, so the digits to recall are all different, and no three digits count up or down by one.
- Trial
- A fixation cross for 1,000 ms, the digits, then recall.
- Recall
- The last digits in order, typed, or tapped on a keypad of 1 to 9 on touch screens, with Delete and Submit. Untimed; every place needs a digit.
- Practice
- Two lists asking for the last 3, with 2 and 1 extra digits, each followed by the digits to recall, the digits entered and how many were in place.
- Score
- The running span score: digits in place on lists that ran on, overall and for each number of digits. Whole lists are scored apart.
Broadway and Engle used letters and let participants skip an item they could not recall; here the items are digits and every place needs a digit. The pace is set before the session and never changes. No published norms are applied.
Quality checks
Each session is marked valid, needs review or invalid, with the reason, before you see its scores.
Scored rows: test-phase recall entries of the scored run, one per list. Recalling several digits in order has no meaningful chance level, so accuracy is not judged against chance; recall is untimed, so nothing can be missed. Fewer than 90% of the planned lists invalidates. No digit in place on the lists that ran on is flagged. A hidden tab withholds the percentile.
Why these rules
Guessing three digits in order succeeds about once in 730 tries, so chance is not meaningful, and a low score can be a real result: the fast pace of Broadway and Engle (2010) gave young adults a mean of 34% in place. A hidden tab lets the study, delay or response timers run without the participant, so a percentile is withheld after one.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Time from one digit to the next (ms) | 2,000 | 500 to 2,500 |
| Most digits to recall | 7 | 6 to 8 |
Yearly plans can change settings within these limits. Free and pay-as-you-go studies use the standard settings.
Need a setting this test does not have?
Devices and languages
- Untimed test: runs on desktops, laptops, tablets and phones. Participant devices
- Languages: English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese.
- Available on: Every plan, including the free plan.
- Recruiting online? See the setup guides for Prolific, Sona Systems, CloudResearch Connect and Qualtrics.
Cite and describe
Participants completed the Running Span task in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Pollack, Johnson and Knaff, 1959; Broadway and Engle, 2010), with the standard settings (time from one digit to the next (ms): 2,000; most digits to recall: 7). The main score was running span score (digits entered in their place among the digits to report, on the lists that ran on past them. 0 to 75 at the standard settings).
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Pollack, I., Johnson, L. B., & Knaff, P. R. (1959). Running memory span. Journal of Experimental Psychology, 57(3), 137-146. https://doi.org/10.1037/h0046137The method: lists of unpredictable length, with the last items recalled.
- Broadway, J. M., & Engle, R. W. (2010). Validating running memory span: Measurement of working memory capacity and links with fluid intelligence. Behavior Research Methods, 42(2), 563-570. https://doi.org/10.3758/BRM.42.2.563Parts by the number of items to report, lists running on by 0 to 3 items, 300 ms items at one every 500 or 2,000 ms, and strict serial scoring.
- Bunting, M., Cowan, N., & Saults, J. S. (2006). How does running memory span work? Quarterly Journal of Experimental Psychology, 59(10), 1691-1700. https://doi.org/10.1080/17470210600848402Holding items passively until the list ends, or updating them while it runs.
Source papers
- Broadway JM, Engle RW (2010). Validating running memory span: Measurement of working memory capacity and links with fluid intelligence. Behavior Research Methods, 42(2):563-570.Paradigm source, Adults aged 18 to 35
Questions
How long does the Running Span take?
About 9 to 11 minutes, as listed in the test library.
What device does a participant need?
Untimed test: runs on desktops, laptops, tablets and phones. The browser must be Chrome, Edge, Firefox or Safari.
What scores does it produce?
Running Span Score, Digits in Place, Last 3 Digits, Last 4 Digits, Last 5 Digits, Last 6 Digits, Last 7 Digits, Last 8 Digits, Whole Lists, Lists Fully Recalled, Median Entry Time, Lists Completed and Planned Lists. Each session is also marked valid, needs review or invalid, with the reason.
How widely is the Running Span used in research?
17 papers from 2021 to 2025 name it in their title or abstract, down 41% compared with 2016 to 2020. That ranks it 342 of 395 test families in the ConductCognition test census (use grade E). Source: ConductCognition test census 0.14.0, counted 31 October 2026 from OpenAlex and ClinicalTrials.gov.
How much reliability evidence does the Running Span have?
In the published research, 1 paper reports its test-retest reliability and 5 registered clinical studies use it as an outcome (evidence grade C in the ConductCognition test census).
Which settings can a researcher change?
Time from one digit to the next (ms) (500 to 2,500) and most digits to recall (6 to 8). Settings can be changed on yearly plans; free and pay-as-you-go studies use the standard settings.
Which languages can participants use?
Participants can take this test in English, Spanish, French, German, Italian, Portuguese (Brazil), Chinese (Simplified) and Japanese. English is on every plan, and the other languages come with yearly plans. Have a native speaker read the machine-translated text before launch.
Is this a clinical test?
No. ConductCognition is for research use only. It runs, scores and exports the test; clinical interpretation is outside the platform.
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