1. 37.4 Blog Post Identify the IV and the DV and explain how to control confounding variables

2. Study 1 - Eating carrots helps you see in the dark! Dr Kipuwel is convinced that if you eat at least two carrots a day for two months, your night-time vision will improve. He sets up an experiment to investigate this, using an independent samples design and randomly allocating his 20 participants between the two groups: each person in group 1 eats 2 carrots a day for two months, and people in group 2 do not eat any carrots for two months. He tests his participants’ night-time vision with a standard eye-test chart of 40 letters, in a darkened room, before the experiment and after the two months are finished. IV: the number of carrots the participants eat DV: the participant’s night-time vision Confounding variables: food the participants daily ingest How I would control them: ask the participants to not eat food related to improving functions of eyes. / or to eat suggested food.

3. Study 2. Does sleeping 8 hours or more a night improve your maths? Ms Vector would like to improve her sleepy students’ maths results. She is horrified to learn that they party till late at night and believes that if they slept more they would improve their maths. The students allocated themselves randomly to two groups: group 1 will sleep at least 8 hours a night for a week; group 2 will continue to have fun, and sleep for about 6 hours or fewer a night. Ms Vector does not know who is in each group. At the end of one week, the students will sit another maths test, and she hopes the results for at least half of them will be better than the test results were last week! IV: sleeping hours DV: Mathematic skills / scores / Maths results Confounding variables: individual abilities / condition of the students at that day How I would control them: ask the students to get intelligence test

4. Study 3. Can meditation lower your blood pressure? Professor Nostress leads meditation classes and is trying to convince his friends that meditating for 15 minutes every day will reduce blood pressure. He sets up an independent measures study: first he takes the blood pressure of 30 volunteers, and then he assigns them randomly to two groups. Group 1 meditates every day with Professor Nostress, and Group 2 does no meditation. After a month, he takes their blood pressure again and notes the results. IV: the hours the participants meditated / meditation DV: the level of blood pressure Confounding variables: food the participants daily eat and exercising would affect the experiment How I would control them: ask the participants to follow the daily plan the researchers have made for the experiment.

5. Study 4. The Halo Effect. Ms Likeable made two videos for a dating website. In the first video, she read the script in an upbeat manner, whereas in the second, she read the same script in a more monotonous fashion. The first video was given to one group of men and the second was given to another group, who watched the video in a separate room. The men who watched the upbeat video found Ms Likeable to be pleasant (as measured on a 1-7 scale) while the men who watched the second video found her to be unpleasant, even though she had read the exact same script. IV: DV: Confounding variables: How I would control them:

6. Study 5. Praise improves individual sporting perfomance Tennis Coach Speedy is frustrated by the playing of his tennis players. Their performance in each game becomes worse instead of better, so he decides to try praising what they do well and downplaying their faults. But to be sure that if their performance improves it is due to praise, he praises those players whom he coaches on Monday, Tuesday and Wednesday, and does not change his behaviour with those he coaches on Thursday, Friday and Saturday. After a month, he compares their results in their next tennis game with the game that they played immediately before his experiment started. IV: DV: Confounding variables: How I would control them: