How does Pattern Trio work?
Nine cards lie on the board. Each shows a shape (circle, square or triangle), a number of them (one, two or three) and a fill (outline, striped or solid). Tap three cards that form a trio. A right trio is replaced by three new cards; a wrong one counts as a mistake. You have 2 minutes to find as many as you can, and the board always holds at least one trio.
What makes three cards a trio?
Look at one feature at a time. For shape, the three cards must all have the same shape or three different shapes. The same goes for the number and for the fill. If any feature has two cards alike and one different, it is not a trio. Three solid circles, two solid circles and one solid circle is a trio: shape same, fill same, number all different.
How do you find trios faster?
Pick any two cards and work out the third. For each feature, if the two cards match, the third must match too; if they differ, the third must be the remaining value. That always gives exactly one card, so the question becomes: is it on the board? Scanning pairs this way is quicker than staring at all nine at once.
There are 27 different cards, and they hold 117 trios between them. The site's tests check both numbers, and that any two cards are completed by exactly one third. It is possible to lay out nine cards with no trio at all, which is why the board is checked before you see it.
How is your result calculated?
Your result is the number of trios you found in 2 minutes. You also see your wrong picks, your accuracy and the average time per trio.
The idea comes from the card game SET, invented by Marsha Falco in 1974, which uses four features and colour. Pattern Trio uses three features and no colour, so it can be played without telling colours apart. For another game about finding the rule, try the Matrix Reasoning Test; for a search against the clock, the Visual Search Test.