AP Psychology - Variables & Groups

Dr. Acula is conducting a study to see if a new energy drink improves memory recall. She gives one group of participants the energy drink and another group a glass of water. Both groups then take a memory test. What is the independent variable?

• The group that received the glass of water.

• The participants' scores on the memory test.

• The gender of the participants.

• The new energy drink.

A researcher wants to study if listening to thrash metal while studying improves test scores. One group of students studies for an hour while listening to Megadeth and Metallica. A second group of students studies for an hour in a quiet room. The researcher then compares their test scores. Which is the dependent variable?

• The type of music the students listen to.

• The students' test scores.

• The amount of time the students study.

• The students' concentration levels.

A study is being conducted to test a new medication for anxiety. One group of patients receives the new pill, while a second group receives a sugar pill that looks identical. Neither the patients nor the doctors know which pill is which. What does the group receiving the sugar pill represent?

• The dependent variable.

• The control group.

• The independent variable.

• The experimental group.

A psychologist wants to see if a new type of chewing tobacco reduces symptoms of depression. One group of patients receives the new chewing tobacco, while a second group receives no chewing tobacco at all. The psychologist then measures the severity of depression in both groups. Which is the control group?

• The group that receives no chewing tobacco.

• The severity of depression.

• The group that receives the new therapy.

• The type of therapy.

In a study on the effects of sleep deprivation on reaction time, one group of participants is allowed to sleep for 8 hours, while another group is restricted to 4 hours of sleep. After the sleep period, both groups complete a driving simulation test that measures reaction time. Which is the experimental group?

• The amount of sleep the participants get.

• The group that is allowed to sleep for 8 hours.

• The participants' reaction time.

• The group that is restricted to 4 hours of sleep.

A psychologist is studying the effect of different teaching methods on student engagement. One class is taught using a couch-based approach, while a second class is taught using an interactive, discussion-based approach. The psychologist then measures the students' level of engagement during the lessons. What is the independent variable?

• The students' level of engagement.

• The number of students in each class.

• The students' prior knowledge.

• The teaching method.

A new weight loss pill is being tested. One group of participants takes the pill. A second group takes nothing. Both groups are on the same diet and exercise plan. What does the group that takes nothing represent?

• The placebo group.

• The control group.

• The experimental group.

• The dependent variable.

A researcher is investigating the effects of caffeine on dance performance. Participants are randomly assigned to one of two groups. The first group drinks a cup of coffee with caffeine, while the second group drinks decaffeinated coffee. After 30 minutes, all participants dance to modern rap music in front of a panel of middle school aged judges who score the performances. What is the dependent variable?

• The amount of caffeine consumed.

• The participants' alertness levels.

• The dance scores.

• The type of coffee the participants drink.

A study is designed to see if a new video game improves hand-eye coordination. One group of participants plays the new video game for one hour per day for a month. A second group spends one hour per day watching competitive eating competitions. Both groups are measured on a hand-eye coordination task before and after the month-long period. Which is the control group?

• The hand-eye coordination task score.

• The group that watches competitive eating competitions.

• The amount of time spent per day.

• The group that plays the new video game.

A psychology teacher is investigating the effects of positive reinforcement on completing homework. One group of students is given a small reward for each assignment they turn in, while another group receives no reward. At the end of the school year, the number of completed assignments for each student is counted. Which is the experimental group?

• The group that receives a reward for each assignment.

• The number of completed assignments.

• The group that receives no reward.

• The type of reward.