How does the Card Sorting Test work?
Four key cards sit at the top: one red circle, two yellow triangles, three green squares and four blue stars. Each new card has a color, a shape and a number of symbols, and you put it on the key card it goes with. There are three ways to match it, and you are never told which is right: only “Right” or “Wrong” after each card.
After 6 right in a row the rule changes, with no warning, and the sort that was right a moment ago is now wrong. The game ends when you have found 6 rules or after 72 cards, whichever comes first. It isn't timed: think as long as you like.
How is the Card Sorting Test scored?
Your result is the number of rules you found, out of 6: each one is a run of 6 right sorts. Right sorts that don't make a run of 6 don't find a rule, so the result also lists every rule that came up and your longest run under each one you missed. Beside it are your right sorts, your mistakes and your repeated-rule errors. A repeated-rule error is a wrong sort by the same rule as the card before, when that card was wrong too: you were told the rule didn't work and used it again. It is the clearest sign of being stuck on an old rule.
Some mistakes can't be avoided. Even a player who reads every “Right” and “Wrong” perfectly can't see a change coming, so the first card after each change is always wrong; then the new rule is one of two. Worked out exactly and checked by simulating that player, a perfect reader makes 8.5 mistakes on average and never more than 12, and no repeated-rule errors at all. The deck has 72 cards: 36 right sorts finish the game, which leaves room for 36 mistakes, 3 times what perfect reading can need, so a slip or two costs you a run, not the game.
How do you do well on the Card Sorting Test?
- Test one rule at a time. Pick color, shape or number and keep to it until you are told “Wrong”. Changing on a hunch loses the run you had built.
- A “Wrong” after a run of rights means the rule changed. Don't go back to the old rule on the next card: it has just failed. Try one of the other two.
- Remember what you have ruled out. If the second guess fails too, the third rule is the only one left.
Is this the Wisconsin Card Sorting Test?
No. It is a recreational game in the same format, not the clinical test, and it gives no diagnosis. The task goes back to David Grant and Esta Berg (1948), whose card-sorting problem became the Wisconsin Card Sorting Test. That test uses its own cards and 128 of them, a trained examiner and norms for each age. This version uses its own symbols and colors, and deals only the 24 cards that match each key card on one feature at most, as in Hazel Nelson's shortened version (1976). So “Right” always tells you which rule you used. Nelson dealt each card twice and announced every change; here the change is never announced, which costs mistakes nobody can avoid, so each card comes 3 times.
What can affect your Card Sorting Test result?
Luck plays a part at the start. The first rule is one of three, so even perfect reasoning finds it after 0, 1 or 2 mistakes, equally often; every later change costs 1 or 2. Attention plays a bigger one: losing count, or missing that a “Wrong” came after a long run, costs more than the rules ever do. Speed doesn't matter, since nothing is timed. Every card names its color in words, so color blindness doesn't stand in the way. If you like rule switching, the Multitasking Test tells you the rule and times how fast you switch; the Stroop Test asks you to ignore the wrong one.