How long does the Card Sorting Test (Berg) take?
About 6 to 10 minutes, as listed in the test library.
Executive Function
Card Sorting Test (Berg)
Measure set shifting and perseveration as participants find sorting rules from feedback and adapt when the rule changes.
Useful for neuropsychology, psychiatry, aging, brain injury, and executive-function research.
Run it with participant credits from $0.99 per participant, or any yearly plan. Preview any test free after you sign up.
Executive function6-10 minUntimedPaid plans and pay as you go
RightMatched by color
Perseverative errorsCategories completed
Sort each card; the rule changes without warning
What the participant sees
One trial, screen by screen, with the timings the test uses.
Until a click on a key card, no time limit
The four key cards and a card to sort
1,000 ms
Right or Wrong
Participants click or tap the key card they choose. There is no time limit.
Example stimuli
Taken from the test's own stimuli.
Key card 1
1 red triangle
Key card 2
2 green stars
Key card 3
3 yellow crosses
Key card 4
4 blue circles
To sort: 3 red stars
Same color as key card 1, same shape as key card 2, same number as key card 3.
To sort: 1 green circle
Same number as key card 1, same color as key card 2, same shape as key card 4.
Session structure
Color
Category 1
Shape
Category 2
Number
Category 3
Color
Category 4
Shape
Category 5
Number
Category 6
Scores and how they are computed
- Perseverative Errorscount
- Errors that follow the rule of the previous category, counted from the first rule change. The scorer replays every rule from the cards and the key cards chosen.
- Lower is better
- Perseverative Errors (%)%
- Perseverative errors per 100 cards sorted.
- Lower is better
- Categories Completedcount
- A category is complete after 10 correct sorts in a row; the rule then changes. Scores run from 0 to 6.
- Higher is better
- Total Errorscount
- Sorts that did not follow the rule in force.
- Lower is better
- Failures to Maintain Setcount
- Errors made after 5 or more correct sorts in a row within a category.
- Lower is better
- Cards to First Categorycount
- Cards sorted up to and including the one that completed the first category.
- Lower is faster learning
- Conceptual Level Responses (%)%
- Correct sorts that are part of runs of three or more correct sorts, per 100 cards.
- Higher is better
Example dataOne simulated session, scored by the code that scores your study's sessions.
- Perseverative errors
- 16
- Categories completed
- 6
- Total errors
- 20
- Cards to first category
- 10
| Sorts, in order (R right, W wrong) | R R R R R R R R R R W W R W R R R R R R R R R R W W W R W W R W R R R R R R R R R R W W W R R R R R R R R R R W W R W W R R R R R R R R R R W W W W R R R R R R R R R R |
|---|
What this task measures
Measures set shifting and perseveration. Participants sort cards by color, shape or number, learn the rule from Right and Wrong feedback, and have to notice when it changes without warning.
Core constructs
- Set shifting
- Perseveration
- Learning from feedback
Research fit
- Neuropsychology and executive-function research
- Psychiatric and neurological group comparisons
- Repeated testing in longitudinal studies
Paradigm overview
The card sorting test measures how people find a rule from feedback and let go of it when it stops working. Four key cards stay at the top of the screen: one red triangle, two green stars, three yellow crosses and four blue circles. Each new card has a color, a shape and a number of symbols, and participants sort it under one of the key cards. They are told only whether each sort was right or wrong.
The rule in force is color, then shape, then number, then the same order again. It changes without warning after 10 correct sorts in a row. The test ends after six completed categories or when the deck runs out: 128 cards by default, or 64 in the short form. Each run of 64 cards holds every combination of color, shape and number once, in an order drawn from the session's random seed. There is no time limit, and the cards are buttons that work with a mouse or by touch.
Perseverative errors are errors that follow the rule of the previous category, counted from the first rule change. Scores also include categories completed, total errors, failures to maintain set (an error after 5 or more correct sorts in a row), the cards needed to complete the first category, and the share of correct sorts in runs of three or more. These definitions follow the published task; the scores are not interchangeable with those of the commercial Wisconsin Card Sorting Test manual.
Task design as built
The trial sequence participants see, as the test runs in ConductCognition. Settings a researcher can change are listed below.
- Key cards
- One red triangle, two green stars, three yellow crosses and four blue circles.
- Rule
- Color, then shape, then number, then the same order again; it changes without warning after 10 correct sorts in a row.
- End
- After 6 categories or when the deck runs out: 128 cards, or 64 in the short form.
- Deck
- Each run of 64 cards holds every combination of color, shape and number once, in an order drawn from the session's seed.
- Feedback
- Right or Wrong for 1,000 ms after each sort.
- Responses
- Click or tap a key card; no time limit.
Perseverative errors here are errors that follow the previous category's rule. The test follows the published Berg task.
Data you get
Every response is saved as it happens. Download scores for all plans, and every trial on yearly plans or with participant credits.
Trial columns for this test
- trial_number
- Order of the sort in the session.
- card_color
- Color of the card sorted.
- card_shape
- Shape of the card sorted.
- card_number
- Number of symbols on the card sorted.
- chosen_key
- The key card chosen, 1 to 4 from the left.
- matched
- The dimensions the card shares with the key card chosen, such as color+number, or none.
- rule
- The rule in force: color, shape or number.
- category_number
- The category the sort belongs to, 1 to 6.
- correct
- Whether the sort followed the rule in force.
- category_completed
- Whether this sort completed a category.
- consecutive_correct_after
- Correct sorts in a row after this one.
- rt
- Time to choose, in ms.
- random_seed
- Seed of the deck order, to rebuild it.
Columns in every export
- participant_id
- Short participant code, the same in every file of the study.
- external_id
- Your own participant ID, when you add one.
- test_version
- Task version the session ran.
- scoring_version
- Scoring version the scores came from.
- customization_status
- standard, or scored_modified when the study changed a setting.
- configuration_json
- The task settings the session ran with.
- is_valid
- The session's quality status (scores file).
- quality_primary_reason
- The main reason when a session needs review or is invalid (scores file).
- started_at
- When the session started (scores file).
- completed_at
- When the session ended (scores file).
Quality checks
Each session is marked valid, needs review or invalid, with the reason.
Scored rows: the scored run's sorts. Accuracy is not judged against chance. Sorting 90% of cards under one key-card position invalidates when accuracy is not above chance (25%), because the correct position changes from card to card. Answers under 200 ms on at least half the sorts invalidate. Completing no category in 64 or more sorts is flagged.
No percentile. Scores and quality flags only.
Running this test
Settings you can change
| Setting | Standard | Allowed |
|---|---|---|
| Deck size | 128 cards (standard) | 128 cards (standard), 64 cards (short form) |
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
- Task text: English and Italian.
- Available on: Paid plans and pay as you go.
- No percentile. Scores and quality flags only. How norms work
- Recruiting online? See the setup guides for Prolific, Sona Systems, CloudResearch Connect and Qualtrics.
Cite and describe
Methods text, with the standard settings
Participants completed the Card Sorting Test (Berg) in a web browser (ConductCognition task version 1.0.0, scoring version 1.0.0; Berg, 1948; Grant & Berg, 1948), with the standard settings (deck size: 128 cards). Perseverative errors were the errors that followed the previous category's rule, counted from the first rule change.
ConductCognition versions: task version 1.0.0, scoring version 1.0.0. Every export records the versions each session used, for a methods section.
- Berg, E. A. (1948). A simple objective technique for measuring flexibility in thinking. Journal of General Psychology, 39(1), 15-22. https://doi.org/10.1080/00221309.1948.9918159
- Grant, D. A., & Berg, E. A. (1948). A behavioral analysis of degree of reinforcement and ease of shifting to new responses in a Weigl-type card-sorting problem. Journal of Experimental Psychology, 38(4), 404-411. https://doi.org/10.1037/h0059831
Source papers
Berg EA (1948). A simple objective technique for measuring flexibility in thinking. Journal of General Psychology, 39(1):15-22.
Paradigm sourceAdults
Grant DA, Berg EA (1948). A behavioral analysis of degree of reinforcement and ease of shifting to new responses in a Weigl-type card-sorting problem. Journal of Experimental Psychology, 38(4):404-411.
Paradigm sourceAdults
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?
Perseverative Errors, Perseverative Errors (%), Categories Completed, Total Errors, Failures to Maintain Set, Cards to First Category and Conceptual Level Responses (%). Each session is also marked valid, needs review or invalid, with the reason.
How are perseverative errors counted?
Errors that follow the rule of the previous category, counted from the first rule change. The scorer replays every rule from the cards and the key cards chosen.
What counts as a completed category?
A category is complete after 10 correct sorts in a row; the rule then changes. Scores run from 0 to 6.
Does it report a percentile?
No. Scores and quality flags only.
Which settings can a researcher change?
Deck size (128 cards (standard), 64 cards (short form)). Settings can be changed on yearly plans; free and pay-as-you-go studies use the standard settings.
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 the free plan's tests, or use participant credits for any test.