How long does the Operation Span Task take?
About 15 to 25 minutes, as listed in the test library.
Working Memory
Operation Span Task
Measure complex working memory by combining simple processing judgments with serial letter recall.
Useful for working-memory, executive attention, education, and intervention outcome studies.
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.
Working memory15-25 minUntimed
(3 × 4) + 2 = ?
14
TRUE
FALSE
KRemember the letter
FHJ1KLNPQ2RS3TY
Solve math problems while remembering letters
What this task measures
Measures working memory capacity with the automated operation span procedure. Participants check simple math problems while remembering letters, then recall the letters in order.
Core constructs
- Working memory capacity
- Executive attention
- Serial recall
- Processing under time pressure
Research fit
- Individual-difference studies of working memory capacity
- Cognitive training and intervention outcome studies
- Studies relating working memory to attention control and reasoning
- Remote research batteries with mouse or touch input
Paradigm overview
Operation Span measures complex working memory, the ability to keep letters in mind while solving math problems. On each item the participant solves a short problem, judges whether a shown answer is true or false, and then sees a letter to remember. After each set, the participant clicks the letters in the order shown on a 4 by 3 letter grid, using a Blank button for any letter they forgot.
The task follows the automated operation span procedure of Unsworth et al. (2005). Practice has three parts: letters only, math only, and both together. The math practice sets each participant's time limit for later problems at their mean solving time plus 2.5 standard deviations. The test has 15 sets, three each of 3 to 7 letters in random order, for 75 letters and 75 problems. Each letter shows for 800 ms. A problem that runs past the time limit counts as a speed error and the task moves on to the letter.
Scoring reports the partial span score (letters recalled in the correct position, 0 to 75), the absolute span score (letters from sets recalled perfectly), and math errors split into speed and accuracy errors. Sessions with math accuracy below 85% are flagged.
Key scoring outputs
Partial Span Score
countLetters recalled in the correct position across all 15 sets (0 to 75).
Higher is better
Absolute Span Score
countSum of set sizes for sets recalled perfectly (0 to 75).
Higher is better
Partial-Credit Unit Score
proportionMean proportion of letters recalled in the correct position per set.
Higher is better
Math Accuracy
proportionProblems answered correctly within the time limit, out of all 75 problems.
Below 0.85 flags the session
Speed Errors
countProblems not solved within the participant's time limit.
Lower is better
Accuracy Errors
countProblems where the true or false judgment was wrong.
Lower is better
Low Math Accuracy
flag1 when math accuracy is below 85%; review before analysis.
Informational
Math Time Limit
msThe participant's time limit per problem: mean practice solving time plus 2.5 SD.
Informational
Task design as built
The trial sequence participants see, as the test runs in ConductCognition. Settings a researcher can change are listed below.
- Letters
- F H J K L N P Q R S T Y, each shown for 800 ms.
- Sets
- 15 sets, three each of 3 to 7 letters in random order: 75 letters and 75 problems.
- Problems
- For example (1 × 2) + 1 = ?, then a true or false judgment of a shown answer.
- Time limit
- Each participant's mean solving time in math practice plus 2.5 standard deviations.
- Recall
- Click the letters in order on a 4 by 3 grid, with a Blank button for a forgotten letter.
- Practice
- Letters only, math only, then both together.
- Math criterion
- Sessions below 85% math accuracy are flagged.
Running this test
Settings you can change
This test runs with fixed settings.
Need a different version of this test?
Devices and languages
- Untimed test: runs on desktops, laptops, tablets and phones. Participant devices
- Task text: English and Italian.
- Available on: Every plan, including the free plan.
- Percentiles against a published norm, on paid plans and pay-as-you-go studies. How norms work
- Recruiting online? See the setup guides for Prolific, Sona Systems, CloudResearch Connect and Qualtrics.
Cite this test
ConductCognition versions: task version 2.0.0, scoring version 2.0.0. Every export records the versions each session used, for a methods section.
- Unsworth, N., Heitz, R. P., Schrock, J. C., & Engle, R. W. (2005). An automated version of the operation span task. Behavior Research Methods, 37(3), 498-505. https://doi.org/10.3758/BF03192720
- Turner, M. L., & Engle, R. W. (1989). Is working memory capacity task dependent? Journal of Memory and Language, 28(2), 127-154. https://doi.org/10.1016/0749-596X(89)90040-5
Source papers
Unsworth, Heitz, Schrock & Engle (2005). An automated version of the operation span task. Behavior Research Methods, 37(3), 498-505.
N 25218-35
Research FAQ
Common questions about this online cognitive test
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?
Partial Span Score, Absolute Span Score, Partial-Credit Unit Score, Math Accuracy, Speed Errors, Accuracy Errors, Low Math Accuracy and Math Time Limit. Each session is also marked valid, needs review or invalid, with the reason.
Does it report a percentile?
Yes. Percentiles against a published norm, on paid plans and pay-as-you-go studies. The session needs standard settings, the participant's age and no quality warnings.
Which languages can participants use?
The test's own text is in English and Italian. Italian participant pages come with yearly plans.
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.
Every test: the full test list.
Run this test in your next study
Start free with 10 free participants on any test, then use participant credits or a yearly plan.
Related tests