Classify each of the hypothetical experiments as double blind, single blind, or unblinded. At least one experimental technique will be used more than once. A pharmaceutical company claims that their new eye drop formula is more effective at treating glaucoma than the standard one. A group of doctors decide to test the claim, and they ask their patients to choose which type of eye drop they would like to receive. The doctors keep track of the number of patients prescribed each formula that go blind within five years. A baker wants to test if his customers can taste the difference between his regular and his gluten-free chocolate cupcakes. He gives both cupcakes to each of 100 customers, randomly varying which type of cupcake is presented on the left. After tasting both cupcakes, he asks each customer which cupcake is gluten-free. A marketing researcher hires three different artists to design a new animal spokesperson for his company. The researcher has a favorite but wants to determine which will be most beloved by the American public. He sends out an anonymous online survey with pictures of the three animal spokespersons to 10,000 randomly selected people. In each survey, the position of the animal spokespersons on the screen is randomized. A researcher designs a clinical trial to test if a new medication is effective at relieving heartburn. Each participant in the trial is assigned a random number. Each number is associated with receiving either the medication or a placebo, both of which look and taste identical. The researcher does not have any direct contact with the participants. A psychologist wants to test whether playing classical music or white noise is more effective at getting children to fall asleep. She creates 500 classical music CDs and 500 white noise CDs. The CDs are visually indistinguishable. She assigns one CD at random to each of 1000 parents, and they administer the treatment. She monitors the children's sleep patterns from image-only videos and then asks the parents which type of CD they received. A baker wants to test if his customers can taste the difference between his regular and his gluten-free chocolate cupcakes. He gives both cupcakes to each of 100 customers, randomly varying which type of cupcake is presented on the left. After tasting both cupcakes, he asks each customer which cupcake is gluten-free. A marketing researcher hires three different artists to design a new animal spokesperson for his company. The researcher has a favorite but wants to determine which will be most beloved by the American public. He sends out an anonymous online survey with pictures of the three animal spokespersons to 10,000 randomly selected people. In each survey, the position of the animal spokespersons on the screen is randomized. A researcher designs a clinical trial to test if a new medication is effective at relieving heartburn. Each participant in the trial is assigned a random number. Each number is associated with receiving either the medication or a placebo, both of which look and taste identical. The researcher does not have any direct contact with the participants. A psychologist wants to test whether playing classical music or white noise is more effective at getting children to fall asleep. She creates 500 classical music CDs and 500 white noise CDs. The CDs are visually indistinguishable. She assigns one CD at random to each of 1000 parents, and they administer the treatment. She monitors the children's sleep patterns from image-only videos and then asks the parents which type of CD they received. Answer Bank single blind double blind unblinded