Question 1

In an experimental study, the experimental group consists of the participants:

Accepted Answer

The experimental group is the group that is exposed to the experimental treatment or the changed conditions. This group is compared to the control group, which is not exposed to the experimental treatment. The dependent variable is what is being measured, so it is not relevant to whether a participant is in the experimental or control group. Scoring the highest in the study is also not relevant to determining the experimental group.

Question 2

Researchers who were studying the effects of music on plant growth raised plants in two different rooms.One room had soft music playing 24 hours a day; the other room had no music.In this study, the control group is:

Accepted Answer

The control group in an experiment is the group that is kept under normal, standard conditions and is not manipulated in any way. In this study, the control group would be the plants in the room with no music as they are the group that is not exposed to the experimental treatment (soft music).

Question 3

A confounding variable is:

Accepted Answer

A confounding variable is an uncontrolled variable that can systematically vary along with the independent variable, and can affect the dependent variable. It creates ambiguity in the study, as we can never be certain if the changes in the dependent variable are due to the independent variable or the confounding variable. Therefore, option D is the correct answer as it explains this definition.

Question 4

A confounding variable in an experiment is an uncontrolled variable that:

Accepted Answer

A confounding variable is one that varies systematically with the independent variable, potentially affecting the outcome of the experiment in ways that cannot be separated from the independent variable's effects. Confounding variables therefore reduce internal validity by making it difficult to determine what caused any observed effects.

Question 5

Dr.Krenshaw believes that people who are under stress will develop more colds than people who are not under stress.When he randomly selects 20 participants and exposes them to high levels of stress, he finds that 17 of the participants develop colds.Based on these results, Dr.Krenshaw concludes that stress causes an increase in the number of colds a person experiences.His reasoning may be flawed because in this study:

Accepted Answer

Without a control group for comparison, Dr. Krenshaw cannot determine if the high rate of colds among his participants is due to the stress they experienced or to other factors. The lack of a control group is a major flaw in this study design.

Question 6

A group of researchers wanted to determine whether children behave more aggressively after watching violent television programming.Half the children in the study watch a violent television show; the other children watch a nonviolent television program.In this study, the control group is:

Accepted Answer

The control group is the group that serves as a benchmark for comparison with the experimental group. In this case, the experimental group is the children who watch the violent television show. Therefore, the control group is the group of children who watch the nonviolent television program. This allows the researchers to compare the levels of aggression between the two groups of children to determine the effect of the violent television programming.

Question 7

Roland and Tabitha both take part in a research study that is investigating the effects of sleep deprivation on reaction time.Roland is kept awake for 24 hours straight, while Tabitha follows her normal sleep routine.In this study, Roland is part of:

Accepted Answer

Roland is the one who is being manipulated to experience the experimental condition of sleep deprivation, hence he belongs to the experimental group. The control group is the one that does not receive any treatment or intervention, while the hypothesis group is not a standard term in research. The dependent variable group is also not a standard term and does not fit in this context.

Question 8

Any uncontrolled variable that changes systematically with the independent variable is:

Accepted Answer

A confounding variable is an uncontrolled variable that changes systematically with the independent variable, and therefore, it can influence the results of the study and create a spurious relationship between the independent and dependent variables. It is important to control for confounding variables in research to eliminate their effects on the dependent variable and increase the internal validity of the study.

Question 9

Dale wants to design a good experiment and be sure there are no confounding variables.In other words, Dale wants to avoid:

Accepted Answer

Confounding variables are uncontrolled variables that change systematically with the independent variable. By avoiding this, Dale can ensure that the independent variable is the only factor affecting the dependent variable, making the experiment more reliable and accurate.

Question 10

An experiment that allows for the determination of causality has:

Accepted Answer

Internal validity is the degree to which an experiment allows for the determination of causality. It refers to whether the results of an experiment can be attributed to the independent variable (the cause) rather than other potential factors or confounds. Therefore, the best choice is C.

Question 11

Researchers studying the effects of alcohol consumption tested the physical coordination skills of 21-year-old men who were first assigned to drink a beverage with either 2 ounces of alcohol or no alcohol.In this study, the control group is:

Accepted Answer

The control group is the group that does not receive the treatment, which in this case is the group that drinks the nonalcoholic beverage. This group is used as a baseline for comparison to determine the effects of the alcohol consumption.

Question 12

Kyle believes that patrons in his bar will be more likely to leave a tip if the tip jar already has some money in it, compared to when the tip jar is completely empty.To test this belief, he has the tip jar empty about half the time when a customer approaches the bar; the rest of the time he ensures there is at least $5.00 in the jar when a customer approaches.In Kyle's experiment, the patrons who see the empty tip jar are part of:

Accepted Answer

The control group is the group that does not receive any treatment or manipulation in the experiment. In this case, the patrons who see the empty tip jar are not receiving any manipulation or treatment, and are simply being observed as a comparison to the experimental group (those who see at least $5.00 in the tip jar). Therefore, they are the control group.

Question 13

Jason wants to design a good experiment and be sure there are no uncontrolled variables that change along with the independent variable.In other words, Jason wants to avoid:

Accepted Answer

Confounding variables are variables that are not accounted for in the experiment which might impact the dependent variable. Jason wants to avoid confounding variables to ensure any changes in the dependent variable are solely due to the independent variable being tested.

Question 14

An experiment that does not effectively control for confounding variables lacks:

Accepted Answer

Internal validity is the degree to which an experiment is free from confounding variables, so an experiment that does not effectively control for these variables lacks internal validity. A refers to whether the experiment measures what it's supposed to measure (which is a different concept), B refers to whether the findings can be generalized to other populations or settings, and C is not a valid term in research methodology.

Question 15

Researchers studying the effects of caffeine on reaction times had participants drink either a beverage that contained caffeine or a decaffeinated version of the same beverage.In this study, the experimental group is:

Accepted Answer

The experimental group is the group that is exposed to the independent variable being studied, in this case, the group that drinks the beverage with caffeine. Therefore, the correct answer is D.

Question 16

The extent to which an experiment has effectively controlled for confounding variables is called:

Accepted Answer

Internal validity refers to the ability of an experiment to eliminate or control for confounding variables that may affect the results. Operational validity refers to how well the experiment measures the variables it claims to measure. External validity refers to the generalizability of findings to real-world settings. Central validity is not a commonly used term in psychology or research methodology.

Question 17

In an experimental study, the group of participants who are not exposed to the experimental treatment is:

Accepted Answer

The group of participants who are not exposed to the experimental treatment is called the control group. They are used to establish a baseline for comparison with the experimental group, who are exposed to the treatment. This helps researchers determine the true effects of the treatment by being able to distinguish changes that are a result of the treatment from changes that might have occurred naturally or due to other factors.

Question 18

In an experiment designed to investigate memory processes, one group of participants was given special instructions and asked to create mental pictures of each item on a list of items to be remembered.Another group of participants was given the same list but received no special instructions about how to remember the items.In this study, the experimental group is:

Accepted Answer

The experimental group refers to the group of participants who receive the special instructions, which is the group that is specifically targeted in this experiment to investigate the effectiveness of creating mental pictures in improving memory. Therefore, A is the correct choice. B and D are incorrect, as they refer to all participants in the study. C is also incorrect, as the number of items remembered by each group is not relevant for identifying the experimental group.

Question 19

A group of researchers wanted to determine whether animals would be slower in learning a maze when they had been exposed to a particular drug.Half the animals received low doses of the drug, and the other half did not receive the drug.In this study, the experimental group is:

Accepted Answer

The experimental group in this study is the group of animals that received the low doses of the drug. The researchers are interested in comparing the performance of this group to the control group (the animals that did not receive the drug) in order to determine whether the drug affects their ability to learn the maze. The other options (A, B, and D) do not accurately describe the experimental group.

Question 20

The control group in an experiment is the group that:

Accepted Answer

The control group does not receive any special treatment in regard to the independent variable. Its purpose is to provide a baseline or comparison for the experimental group that does receive the independent variable.

Quiz 2: The Tools of Psychological Research