Concentration

So I have a little Christmas themed concentration game on my iPhone which I downloaded for Erika's benefit. Erika understands the rules of the game now, and it's sort of interesting to watch how she plays. Her basic strategy is to click on a square, and then click on another square. If that isn't a match, then she clicks on the first square again, and then clicks on a third square. And so on, although sometimes she doesn't remember which "third squares" she's clicked on already. She does, however, tend to remember where matches are. So if clicking along on third squares she sees a snowman and knows where the other snowman is, then she'll often get that pair next turn. She doesn't make the negative inferences though: even though she knows that "the snowman is at point X" she doesn't conclude "point X is not the bells".