Experimental Design
The experiment consists of two treatments, as described below. The experiment is played online; subjects are randomly assigned to one of the treatment conditions and keep their treatment assignment throughout the experiment. The experiment consists of 9 rounds; each round of the experiment lasts 60 seconds. In each round of the experiment, subjects can work on two tasks, a Memory game and a Math exercise.
The Memory game (also known as Concentration or Matching Pairs) consists of 10 pairs of cards with two-digit numbers on them. At the beginning of a round, the cards lie face down and can be flipped by a mouse click. Per move, subjects can flip two cards. If they find a pair - i.e., both cards show the same number - the cards stay flipped over. The objective of the task is to find as many pairs as possible. As Math exercise, subjects face three summations, each of which consists of six addends. Their task is to decide which of the three options yields the highest sum. The Math exercise features a default option that is implemented if subjects do not make an active decision. In particular, in each round, one option is randomly selected and displayed as the default choice.
Subjects see one task at a time on their screen and can freely navigate between the two tasks during the duration of each round. They navigate between the two tasks by using tabs at the top of their screen or buttons at the bottom of their screen. At the end of a given round, subjects face a waiting screen, on which they can enter the next round by clicking a button on the screen. Subjects face a new Memory game and Math exercise in each round.
Subjects receive EUR 0.04 for each uncovered pair in the Memory game; they receive EUR 0.20 if they select the option that yields the highest sum in the Math exercise in a given round. All rounds of the experiment are paid out to subjects. Subjects receive feedback on their earnings only after the final round of the experiment.
Treatments vary how tasks are displayed to subjects. When entering a new round in the baseline treatment, the Memory game is displayed to subjects. When entering a new round in the treatment condition, the Math exercise is displayed to subjects. In both treatments, they can freely navigate between tasks by using the on-screen Tabs / Buttons, as described above.