Question 1

A researcher is interested in the effects of a vegetarian diet on memory. One group eats a strict vegetarian diet for three months, a second group eats a strict vegan diet for three months, while a third group eats anything they want for three months. After three months, all participants are given a memory test. The first 20 people who participated were assigned to the vegetarian group, the next 20 to the vegan group, and the final 20 to the eat anything group. What's wrong with this experiment?
A)It is confounded because of a possible experimenter bias effect.
B)The experimenter introduced some demand characteristics.
C)It is confounded because there was no random assignment.
D)It is confounded because the study cannot be replicated.
E)There is nothing wrong with this experiment.

Accepted Answer

The lack of random assignment to the different diet groups means that any observed differences in memory test performance could be due to pre-existing differences between the groups rather than the effect of the diet itself.

Question 2

Which of the following research methods is MOST susceptible to threats to internal validity?
A)Experiments
B)Correlational studies
C)Naturalistic observation
D)Case studies
E)Surveys

Accepted Answer

The answer of Which of the following research methods is...

Question 3

You are trying to find out your friend's IQ. She won't tell you. But she did say that her Z-score on a standard Wechsler test (M = 100; SD = 15) was + 2.0. What's her IQ?
A)100
B)200
C)115
D)130
E)85

Accepted Answer

A Z-score of +2.0 on the Wechsler test, which has a mean (M) of 100 and a standard deviation (SD) of 15, means her score is 2 standard deviations above the mean. Calculating this gives: 100 + (2 * 15) = 130.

Question 4

Let's say that you conduct a study on the effects of vitamin B12 on maze learning in rats. Your statistical analysis reveals that 60% of the variance can be accounted for by the manipulation of vitamin B12. The remaining variance (40%) is referred to as
A)independent variance
B)variable fluctuation
C)factor analysis
D)error variance
E)normal variance

Accepted Answer

The remaining 40% of variance not explained by the manipulation of vitamin B12 is referred to as error variance. This term encompasses all other sources of variability in the data that are not accounted for by the experimental manipulation, including measurement errors, individual differences among subjects, and other uncontrolled variables.

Question 5

Considering the following data set: (3, 4, 4, 0, 4, 1, 5), which of the following statements is true?
A)The range is 4.
B)The median is 0.
C)The mean is greater than the mode.
D)The mode is 4.
E)The range is 2.

Accepted Answer

The mode is the number that appears most frequently in a data set. In this case, the number 4 appears three times, making it the mode.

Question 6

A researcher is interested in the effects of a vegetarian diet on memory. One group eats a strict vegetarian diet for three months, a second group eats a strict vegan diet for three months, while a third group eats anything they want for three months. After three months, all participants are given a memory test. Results indicated that memory was better for both the vegetarian and vegan groups. In this study, the dependent variable is
A)the vegan diet
B)the vegetarian diet
C)the type of diet
D)scores on the memory test
E)not enough information to tell

Accepted Answer

The dependent variable is the outcome that the researcher is interested in measuring, which in this case is the "scores on the memory test." This is because the study aims to observe how different diets (independent variables) affect memory (dependent variable).

Question 7

If you wanted to ensure that any differences among participants in an experiment were as balanced as possible, you would use
A)representative sampling
B)random assignment
C)placebos
D)blind controls
E)only two groups

Accepted Answer

Random assignment is the process used in experimental designs to ensure that each participant has an equal chance of being placed in any group, thus balancing out differences among participants as much as possible.

Question 8

An experimental design in which all participants are exposed to all of the conditions of an independent variable is called
A)a between groups design
B)a repeated measures design
C)a made an error design
D)a counterbalanced design
E)an interaction design

Accepted Answer

A repeated measures design involves the same participants being exposed to all conditions of an independent variable, allowing for direct comparison of their responses across conditions.

Question 9

Considering the following data set: (3, 4, 4, 0, 4, 1, 5), which of the following statements is false?
A)The range is 5
B)The median is 4
C)The median is less than the mean
D)The mode is 4
E)The mean is 3

Accepted Answer

The median of the dataset, when arranged in ascending order (0, 1, 3, 4, 4, 4, 5), is 4. The mean is (3+4+4+0+4+1+5)/7 = 21/7 = 3. Since the median (4) is greater than the mean (3), statement C is false.

Question 10

Professor Jones was just asked to stop conducting one of his experiments. The experiment involved deception and the department chair said that he had failed to live up to his ethical responsibility. Most likely, Professor Jones failed to include which of the following in his study?
A)Post-test assessment
B)Random assignment
C)Double-blind procedure
D)Repeated measures
E)Informed consent

Accepted Answer

Informed consent is a fundamental ethical requirement for research involving human participants. It ensures that participants are fully aware of the nature of the research, including any potential risks or deception, and agree to participate willingly. Failure to obtain informed consent, especially in studies involving deception, would be a significant ethical lapse.

Question 11

Which of the following is/are TRUE of the normal distribution (bell-shaped curve)?
A)The mean is equal to the mode.
B)The mean is equal to the median.
C)50% of the scores fall below the mean.
D)Approximately 68% of the scores fall between -1 standard deviation and +1 standard deviation.
E)All of these choices are correct.

Accepted Answer

All of the statements A through D are characteristics of a normal distribution. The mean, median, and mode are all equal in a perfectly normal distribution. Additionally, 50% of the scores do fall below the mean, and approximately 68% of the scores are within one standard deviation of the mean.

Question 12

Elyse is interested in studying aggression. To do so, she decides to look at horn-honking behaviour at stop signs and records the number of times someone honks their car horn before the car in front moves on. In this example, horn-honking is the _____ and the number of honks recorded is the _____.
A)independent variable; dependent variable
B)dependent variable; independent variable
C)operational definition of aggression; dependent variable
D)controlled variable; measured variable
E)dependent variable; error variance

Accepted Answer

Horn-honking is used as the operational definition of aggression, and the number of honks recorded is the dependent variable because it is the outcome being measured.

Question 13

Which of the following is NOT a part of the scientific process?
A)Identify a question of interest
B)Gather information and form hypothesis
C)Conduct an experiment
D)Analyze data
E)Build a body of knowledge

Accepted Answer

The answer of Which of the following is NOT a...

Question 14

Let's say that the grades on this exam are normally distributed with a mean of 70 and a standard deviation of 10. Approximately what percentage of students will have a grade between 50 and 90 on this exam?
A)50 percent
B)95 percent
C)99 percent
D)80 percent
E)Can't tell from this information

Accepted Answer

Using the 68-95-99.7 rule for normal distributions, approximately 95% of observations fall within two standard deviations of the mean. Since 50 and 90 are two standard deviations away from the mean (70 ± 2*10), about 95% of students' grades will fall in this range.

Question 15

Professor Bono believes that there is a correlation between number of hours spent on social media and grades in first-year classes. Which of the following correlation coefficients would provide the STRONGEST support for her prediction?
A)+.70
B)-.85
C)+.25
D)-.70
E)0.0

Accepted Answer

A correlation coefficient close to -1 or +1 indicates a strong relationship between two variables. In this case, -.85 (B) suggests a strong negative correlation, meaning as hours spent on social media increase, grades decrease, which supports Professor Bono's prediction.

Question 16

Typically, when psychologists conduct an experiment, they are willing to a ___ percent chance that the results are random and are due to chance.
A)five
B)ten
C)one
D)twenty
E)zero

Accepted Answer

Psychologists typically accept a 5% (five percent) chance that their experimental results are due to random chance, which corresponds to a p-value of 0.05. This threshold is widely used in the social sciences to determine statistical significance.

Question 17

A company manager believes that there should be a relationship between total sales for a month (in dollars) and the number of sales people on the floor. Which of the following correlation coefficients shows the strongest support for her belief?
A)0.92
B)-0.67
C)0.0
D)0.33
E)-0.90

Accepted Answer

A correlation coefficient of 0.92 shows the strongest positive relationship between the two variables, indicating that as the number of salespeople increases, total sales also increase significantly.

Question 18

A major difference between experiments and correlational studies is
A)manipulation of independent variables
B)control
C)sampling methods
D)external validity
E)control and manipulation of independent variables

Accepted Answer

Experiments involve the manipulation of independent variables and control over extraneous variables to establish cause-and-effect relationships, distinguishing them from correlational studies which only identify relationships without manipulation or control.

Question 19

Which of the following is NOT a characteristic of a good theory?
A)It is intuitive.
B)It incorporates existing facts and observations.
C)It is testable.
D)It is parsimonious.
E)Predictions are supported by new research.

Accepted Answer

A good theory should be testable, parsimonious, incorporate existing facts and observations, and have predictions supported by new research. Being intuitive is not a necessary characteristic of a good theory, as some theories may initially seem counterintuitive but are supported by evidence and rigorous testing.

Question 20

After writing the licensing exam to practice Psychology, Dr. Evans is sent the following information: Her grade on the exam was 550. The scores on the exam were normally distributed with a mean of 450 and a standard deviation of 100. How well did Dr. Evans do on the licensing exam?
A)Her grade was better than approximately 16% of the other examinees.
B)Her grade was better than approximately 50% of the other examinees.
C)Her grade was better than approximately 84% of the other examinees.
D)Her grade was better than approximately 97% of the other examinees.
E)Dr.Evans received the highest grade on the exam.

Accepted Answer

Dr. Evans scored 1 standard deviation above the mean (550 - 450 = 100). In a normal distribution, scoring 1 standard deviation above the mean is better than approximately 84% of the other examinees.

Quiz 2: Studying Behaviour Scientifically

Which of the following research methods is MOST susceptible to threats to internal validity?

You are trying to find out your friend's IQ. She won't tell you. But she did say that her Z-score on a standard Wechsler test (M = 100; SD = 15) was + 2.0. What's her IQ?

Let's say that you conduct a study on the effects of vitamin B12 on maze learning in rats. Your statistical analysis reveals that 60% of the variance can be accounted for by the manipulation of vitamin B12. The remaining variance (40%) is referred to as

Considering the following data set: (3, 4, 4, 0, 4, 1, 5) , which of the following statements is true?

If you wanted to ensure that any differences among participants in an experiment were as balanced as possible, you would use

An experimental design in which all participants are exposed to all of the conditions of an independent variable is called

Considering the following data set: (3, 4, 4, 0, 4, 1, 5) , which of the following statements is false?

Professor Jones was just asked to stop conducting one of his experiments. The experiment involved deception and the department chair said that he had failed to live up to his ethical responsibility. Most likely, Professor Jones failed to include which of the following in his study?

Which of the following is/are TRUE of the normal distribution (bell-shaped curve) ?

Elyse is interested in studying aggression. To do so, she decides to look at horn-honking behaviour at stop signs and records the number of times someone honks their car horn before the car in front moves on. In this example, horn-honking is the _ and the number of honks recorded is the _.

Which of the following is NOT a part of the scientific process?

Let's say that the grades on this exam are normally distributed with a mean of 70 and a standard deviation of 10. Approximately what percentage of students will have a grade between 50 and 90 on this exam?

Professor Bono believes that there is a correlation between number of hours spent on social media and grades in first-year classes. Which of the following correlation coefficients would provide the STRONGEST support for her prediction?

Typically, when psychologists conduct an experiment, they are willing to a ___ percent chance that the results are random and are due to chance.

A company manager believes that there should be a relationship between total sales for a month (in dollars) and the number of sales people on the floor. Which of the following correlation coefficients shows the strongest support for her belief?

A major difference between experiments and correlational studies is

Which of the following is NOT a characteristic of a good theory?

After writing the licensing exam to practice Psychology, Dr. Evans is sent the following information: Her grade on the exam was 550. The scores on the exam were normally distributed with a mean of 450 and a standard deviation of 100. How well did Dr. Evans do on the licensing exam?