### Learning Gambles from Experience: Instructions

This is a study of decision making in which you can gamble without risk and perhaps even win some money, if you are lucky. At the same time, your participation in this study can help scientists in the Decision Research Center learn more about how people make choices. Decide first if you want to participate. You must be over 18, and each person can participate only once. The task usually takes about 5-8 minutes.

Now, scroll down and look at the first choice, No. 1, in the panel below. Click on the button below "Gamble A" that is labeled "35 Random Draws". You will see that the prizes of Gamble A are either \$0 or \$100, and that about half say "\$0" and half say "\$100". By clicking the button for each gamble, you will see a random selection of possible prizes for that gamble. About half of the prizes of Gamble A are \$0 and half are \$100, but in any sample of 35, there may be more or less than 50% of each. By viewing several samples from each gamble, you can learn more and more precise information about each gamble before you make your decision. By clicking the button under "Gamble B" that is labeled "35 Random Draws" you will see that Gamble B gives prizes of \$25 or \$35, and there are about 50-50 chances of winning either \$25 or \$35. The decision between A and B is the same as the decision to choose either:

A: fifty-fifty chance of winning either \$100 or \$0 (nothing),
OR
B: fifty-fifty chance to win either \$35 or \$25.

Think of probability as the number of tickets in a bag containing 100 tickets, divided by 100. Gamble A has 50 tickets that say \$100 and 50 that say \$0, so the probability to win \$100 is .50 and the probability to get \$0 is .50. If someone reaches in bag A, half the time they might win \$0 and half the time \$100. But in this study, you only get to play a gamble once, so the prize will be either \$0 or \$100. Gamble B's bag has 100 tickets also, but 50 of them say \$25 and 50 of them say \$35. Bag B thus guarantees at least \$25, but the most you can win is \$35. Some will prefer A and others will prefer B.

To mark your choice, click the button marked, "I am ready to choose", and enter either A or B in the space provided. You are required to view at least 3 samples of 35 from each gamble before you choose (the number of times you have viewed each gamble will be shown in the box just above the buttons); however, you are permitted (and encouraged) to view more than 3 samples--you may view as many samples from each gamble as you like before you make your decision.

Once you press the "I am ready to choose" button, you are no longer permitted to view those two gambles again, so please do not press the "cancel" button once you are asked to make a choice. That will send you to the next two gambles without registering your decision.

In the warmup there are three choices, but in the main experiment, you will be presented with 12 different choices. On June 21, 2004, after people have finished their choices, three participants will be selected randomly to play one gamble for real money. One trial will be selected randomly from the 20 trials, and if you were one of the 3 lucky people selected, you will get to play the gamble you chose on the trial selected. You might win as much as \$110. Any one of the 12 choices might be the one you get to play, so choose carefully. Winners will be notified by email. Offer void where prohibited by law.

 Choice Number =