Question 1

Research participants are randomly assigned to different groups in an experiment in order to

Accepted Answer

Random assignment is used in experiments to ensure that each group is similar to the others in terms of participant characteristics at the start of the experiment. This minimizes pre-existing differences between the groups, allowing the researcher to attribute any differences in outcomes to the experimental manipulation rather than to pre-existing differences among participants.

Question 2

In a test of the effects of sleep deprivation on problem-solving skills,research participants are allowed to sleep either 4 or 8 hours on each of three consecutive nights.This research is an example of

Accepted Answer

This is an experiment because the researcher is manipulating the independent variable (amount of sleep) and measuring the dependent variable (problem-solving skills) while controlling for extraneous variables.

Question 3

Being randomly assigned to the experimental group in a research project involves being assigned

Accepted Answer

Random assignment means that each participant has an equal chance of being assigned to the experimental group by chance, without any bias or manipulation by the researcher. This ensures that the groups are comparable in all aspects except for the independent variable, which increases the confidence in the causal relationship between the independent and dependent variables. The other options (B, C, D) are incorrect because they do not fully capture the essence of random assignment and may suggest alternative or incorrect reasons for the grouping of participants.

Question 4

To study the potential effects of social interaction on problem solving,some research participants were instructed to solve problems by working together;other participants were told to solve problems by working alone.Those who worked alone were assigned to the ________ group.

Accepted Answer

The participants who worked alone were the group used as a comparison or "control" group, as they were not exposed to the variable being studied (social interaction in problem solving). The other group, who worked together, was the experimental group. A survey group would involve participants answering questions rather than completing a task, and a correlational group would involve examining the relationship between two variables rather than manipulating one variable to see its effect on another.

Question 5

An experiment enables researchers to isolate the effects of one specific factor by manipulating the factor of interest and also

Accepted Answer

Holding other factors constant across experimental and control groups is the best choice to isolate the effects of one specific factor. This allows the researchers to see if changes in the factor of interest are responsible for changes in the outcome variable, rather than other variables that may be present in the environment or in the participants themselves. Obtaining informed consent, summarizing responses on a scatterplot, and debriefing participants are important ethical considerations in conducting research, but are not directly related to isolating the effects of one specific factor.

Question 6

The most foolproof way of testing whether a newly introduced method of psychological therapy is truly effective is to use

Accepted Answer

The most effective way to determine the effectiveness of a psychological therapy method is through experimental research. This involves having a control group and an experimental group and manipulating the independent variable to measure if there is a significant difference in outcomes between the two groups. This helps remove confounding variables and provides the most reliable results.

Question 7

The group exposed to a newly created drug that is being tested in an experiment is called the ________ group.

Accepted Answer

The group exposed to the newly created drug is the experimental group, as they are the group being tested to see the effects of the drug. The control group, on the other hand, is the group that does not receive the drug and is used as a basis for comparison. The terms standardized and baseline do not refer to a specific group in experiments.

Question 8

To accurately isolate cause and effect,experimenters should use

Accepted Answer

Random assignment is the most effective way to eliminate the influence of extraneous variables and establish a cause-and-effect relationship between the independent and dependent variables. This method involves randomly assigning participants to either a control group or an experimental group, and manipulating the independent variable only for the experimental group while keeping all other conditions the same for both groups. This way, any observed differences in the dependent variable can be attributed to the effects of the independent variable. Naturalistic observation, case studies, and correlation coefficients cannot establish causality as rigorously as random assignment can.

Question 9

Both the researchers and the participants in a memory study are ignorant about which participants have actually received a potentially memory-enhancing drug and which have received a placebo.This investigation involves the use of

Accepted Answer

The scenario describes the use of the double-blind procedure, where both the researchers and participants are unaware of who received the drug or placebo. This helps to eliminate any potential biases or expectations from affecting the results of the study.

Question 10

In which type of research would an investigator manipulate one factor and observe its effect on some behavior or mental process?

Accepted Answer

The type of research described in which an investigator manipulates one factor and observes its effect on some behavior or mental process is called experimentation. This involves manipulating an independent variable and measuring its effect on a dependent variable. This allows researchers to establish cause-and-effect relationships between variables. The other options, such as surveys, case studies, and naturalistic observation, do not involve the manipulation of variables in the same way as experimentation.

Question 11

Participants in an experiment are said to be blind if they are uninformed about

Accepted Answer

Participants are considered blind if they don't know which experimental treatment they are receiving. This is known as a single-blind study. It helps minimize the potential for bias, as participants may respond differently if they know which treatment they are receiving. The other options (A, B, and C) are not related to whether participants are blind or not.

Question 12

To assess the impact of test difficulty on persistence of effort,researchers plan to give one group of children relatively easy tests and another group more difficult tests.To reduce the chance that the children in one group are more intelligent than those in the other group,the researchers should make use of

Accepted Answer

Random assignment will ensure that any individual differences in intelligence are evenly distributed among the two groups, reducing the chance that one group is inherently more intelligent than the other. The other choices (B, C, and D) are not relevant to addressing the issue of potential differences in intelligence between the two groups.

Question 13

Researchers use experiments rather than other research methods in order to isolate

Accepted Answer

Experiments are specifically designed to manipulate independent variables and observe their effects on dependent variables, allowing researchers to isolate causes from effects. Other research methods, such as case studies and surveys, do not manipulate variables in this way and may not be able to determine causality. While experiments can also generate data for theory testing, this is not the primary reason why researchers use them. Random and representative sampling techniques are used to ensure that the sample of participants in a study is representative of the larger population, but this is not the main reason why experiments are used over other research methods.

Question 14

One research team randomly assigned hospitalized premature infants either to formula feedings or to breast-milk feedings.Which research method did they use?

Accepted Answer

This research team used experimentation as they randomly assigned infants to two different feeding methods to determine the effects of formula versus breast milk on premature infants.

Question 15

A negative correlation between degree of wealth and likelihood of suffering from a psychological disorder would indicate that

Accepted Answer

A negative correlation means that as one variable increases, the other variable decreases. So in this case, as degree of wealth increases, likelihood of suffering from a psychological disorder decreases. Therefore, option B is the best choice, as it correctly states that people who are poor are more likely to have a psychological disorder than are wealthy people. Option A is incorrect because it implies that poverty directly causes psychological disorders, which is not necessarily true. Option C is incorrect because it implies that having a psychological disorder directly prevents someone from accumulating wealth, which is also not necessarily true.

Question 16

Which of the following is true for those assigned to a control group?

Accepted Answer

Participants assigned to a control group do not receive the experimental treatment and serve as a comparison to the experimental group. Therefore, the experimental treatment is absent in the control group.

Question 17

Which of the following methods is most helpful for clarifying cause-effect relationships?

Accepted Answer

The experiment is the most helpful method for clarifying cause-effect relationships because it allows the researcher to manipulate the independent variable and observe its effects on the dependent variable while controlling for other variables. This allows for the establishment of a causal relationship between the independent and dependent variables. The other methods listed (survey, correlational research, and naturalistic observation) do not allow for the establishment of causality.

Question 18

Which research method provides the best way of assessing whether cigarette smoking boosts mental alertness?

Accepted Answer

The experiment provides the best way of assessing whether cigarette smoking boosts mental alertness because it allows researchers to manipulate the independent variable (smoking) and measure the effect on the dependent variable (mental alertness) while controlling for extraneous variables. This allows for establishing cause-and-effect relationships and controlling for alternative explanations. The other research methods (case study, survey, naturalistic observation) may provide useful information, but they do not allow for as much control over variables or establishing causality.

Question 19

Research participants drank either caffeinated or decaffeinated beverages in a study of the effects of caffeine on anxiety levels.Those who received the caffeinated drinks were assigned to the ________ group.

Accepted Answer

The participants who received the caffeinated drinks were part of the experimental group, as they were the group that was being manipulated with the independent variable (caffeine) to measure its effects on anxiety levels. The decaffeinated group would be considered the control group, as they were used as a comparison to the experimental group to determine if any observed differences in anxiety levels were due to the presence of caffeine or another factor.

Question 20

To assess the effectiveness of flu vaccine for county residents,Mr.Carlson wants to administer vaccine injections to all county residents rather than give half of them a placebo injection.Mr.Carlson is most clearly underestimating the importance of

Accepted Answer

Mr. Carlson is not including a control group in his study, which is crucial in determining the effectiveness of the flu vaccine. Without a control group, it is impossible to compare the outcomes of those who receive the vaccine to those who do not, and it is difficult to rule out alternative explanations for any observed effects. Testing a large sample, operationally defining procedures, and replicating observations are all important aspects of conducting a rigorous study, but they do not address the specific issue of whether the vaccine is effective compared to a placebo or control group.

Quiz 2: Thinking Critically With Psychological Science