Experiments

1. For each hypothesis, consider how you could design a study that would test it, then in the experiment that’s given, identify the independent and dependent variables. Experiments

2. Experiments • Hypothesis: Taking tests in hot rooms decreases test scores. • Students are randomly assigned to take a test in either a hot room or a comfortable room. Test scores will be compared to see if hot rooms negatively affect test-taking. • What is the independent variable? • Students • Room temperature • Test scores • Tests • What is the dependent variable? • Students • Hot room • Comfortable room • Test scores

3. Experiments Hypothesis: Newborns gaze longer at a drawing of a face-like image than at a bull’s-eye pattern. Newborns are shown, in random order, the stimuli: A face-like image, a bull’s-eye pattern, and a blank screen. Each newborn is timed to see how long they look at each. • What is the independent variable? • Random order • Length of gaze • The stimuli • Newborns • What is the dependent variable? • Newborns • Length of gaze • Facelike image and bull’s-eye pattern • All of the stimuli

4. Experiments Hypothesis: Without their sense of smell, it may be difficult to distinguish a cold cup of coffee from a glass of red wine. Participants are blindfolded and their noses are pinched closed. They are then presented with a cold cup of coffee, a cup of red wine, and a cup of water, in random order. Each is presented 3 times. Participants are asked to sip each one, guessing the contents of the cup. Next the participants, still blindfolded but with unpinched noses, taste the contents of each cup again, again guessing each cup’s contents. • What is the independent variable? • Being able to smell or not • Participants • The contents of each cup • Identifying the contents of each cup • What is the dependent variable? • Being blindfolded • Participants • The contents of each cup • Identifying the contents of each cup

5. Experiments Hypothesis: Televised violence leads to aggressive behavior by teenagers who watch the programs. Teenagers ages 15-17 are randomly assigned to watch either a violent movie or an equally engaging but non-violent movie. Afterwards while playing a game, they are given an opportunity to punish their competitor by blasting a loud sound in their competitor’s headphones. The teenage participants get to choose how long to administer the sound. • What is the independent variable? • The competitor • Type of movie • Length of the loud sound • Teenage participants • What is the dependent variable? • Length of the loud sound • Violent movie • Teenage participants • Game competitor

6. Experiments Hypothesis: When people learn something while intoxicated, they recall it best when they are again intoxicated. Participants are given enough alcohol to become intoxicated, and then they watch a 30-minute instructional video. The next day the participants are randomly divided into two groups. One group is again given the same amount of alcohol as they had the previous day. The other group is given a glass of water with a little vodka around the rim. Both groups are given a test on the material covered in the video. • What is the independent variable? • Alcohol • Intoxicated again or not • Test scores • Instructional video • What is the dependent variable? • Being intoxicated • Vodka on the rim of the glass • Participants • Test scores