Rule discovery and rule change

Card sorting by a rule that changes without telling you

Put each card on one of four piles. All you are told is right or wrong, and once ten sorts in a row come back right, the rule quietly becomes a different one. The run measures less how quickly you find a rule than how expensively you let go of one — the count printed largest at the end.

64-card deck
Rule changes silently
Raw counts, no percentile

A card appears; you put it on one of four piles. Nobody tells you what makes a pile the right one — the only information you get is the word right or wrong after each card, and once you have found the rule it changes, without any announcement, and keeps changing. Up to 64 cards, usually four to seven minutes.

The procedure, in full

Piles: one red triangle, two green stars, three yellow crosses, four blue circles
Deck: all 64 combinations of the four colors, four shapes and counts one to four, shuffled fresh
Feedback: the word right or wrong for 480 ms, then a gap of 140 to 260 ms drawn at random so the next card cannot be timed
Change: 10 correct sorts in a row complete a category and the rule silently becomes the next one
Order: drawn at random for this run, not the published sequence
Spill: a click inside 100 ms of a card appearing belongs to the previous card; that card leaves the deck uncounted
Ends: at the 64th card or the 6th category, whichever arrives first

Which of the three came up first, and in what order the rest followed, is held back until the deck is finished.

The paradigm: Grant & Berg (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

Print each card's color, shape and count underneath it. Worth switching on if red and green are hard to tell apart: naming the attributes gives away nothing, because the difficulty here has never been in seeing them.

The practice cards are announced as a color sort and are drawn separately, so they cost you none of the 64 and tell you nothing about which rule the deck opens on.

Finding a rule is easy. Dropping one is the test

A card can match a pile on three things only: color, shape, or the number of symbols. Almost everyone finds the rewarded one within a handful of cards. The trouble starts at the change, because by then the old rule has been confirmed ten times and the card contradicting it has been seen once. A wrong sort made there, by the rule that has just stopped paying, is a perseverative error, and it is counted apart from the rest.

The split is the point of the paradigm. Before you have any rule, a wrong sort is a guess and tells nobody much. A wrong sort straight after a change is a card placed by an idea the feedback has already withdrawn. Lump them together and a person who was guessing looks identical to a person who could not let go. Here an error is perseverative when the pile you chose matches the card on the dimension that was right until the last change and not on the one rewarded now — the definition is printed in the result beside the count, so you can check every card it was applied to.

The arrangement — a card, piles it could join on more than one attribute, and a rule the participant has to infer and the experimenter then changes — was set out in Grant & Berg (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. Its later fame as a frontal-lobe examination is a claim this page does not make: high error counts also come with poor sleep, anxiety, an unfamiliar interface or simply not caring much about a website, and a browser has none of the controls that make a clinical administration readable.

This is a measurement exercise, not a clinical assessment. It reports what you did on this page against a stated reference and nothing more — it cannot establish a frontal-lobe impairment, ADHD, schizophrenia or any other condition. Only a qualified professional, working with more than a browser, can make that judgment.

What this version changes, and why

The rule order is shuffled. Color, shape and count are put in a random order each run and then cycled. The published order is fixed and widely reprinted, and anyone who had read it would get the first category free.
Nothing announces a category. There is no streak counter and no signal that ten have been reached. Watching a run climb toward ten tells you when the change is due, and a switch you were waiting for costs nothing to make.
The pause between cards is drawn at random. Right or wrong shows for 480 ms, then a gap of 140 to 260 ms, so the next card cannot be anticipated, and a click within 100 ms of a card appearing is set aside as spill-over from the one before.
The labels can be switched on. Each card’s color, shape and count can be printed underneath it in words, which gives nothing away — the difficulty was never in seeing the attributes.

Eight practice cards with the rule given away come first if you want them. Cancelling a response already under way, rather than abandoning a rule, is the stop signal task; planning a sequence of moves before making any is the Tower of London test.

After the deck runs out

The rule changed and I got four wrong in a row. Is four bad?

Not by itself — the shape of the sequence matters more than the count. One or two wrong cards after a switch are close to unavoidable: you cannot know a rule has changed until a card that should have been right comes back wrong, and the second card is where the search begins. What the perseverative count is looking for is the difference between two cards of resistance and eight, and between an error that repeats the old rule and one that tries something new and misses. The table under the result shows both, switch by switch.

How many cards should it take to find the first rule?

This page does not print a target, because there is no defensible one. The first card is a one-in-four guess, the next few narrow it, and from there it depends on what the shuffle deals — cards whose color and shape point at the same pile tell you far less than cards where they disagree. The result reports how many cards your first category took, which is worth comparing with your own next run and with nothing else.

Is this the published Wisconsin card sorting test?

No. It is the sorting paradigm the published instrument was built on, run in a browser: the deck order is generated, the rule order is randomized rather than fixed, and perseveration is counted by the rule stated on the results panel instead of the scoring manual's more elaborate one. The manual and its normative tables are a commercial clinical product and are not reproduced here, so no count on this page can be looked up in them.