Question 1

Which of the following correlation coefficients represents the strongest relationship between two variables?
A) .50
B) .25
C) -.25
D) -.75

Accepted Answer

The correlation coefficient ranges from -1 to 1, with -1 indicating a perfect negative relationship, 0 indicating no relationship, and 1 indicating a perfect positive relationship. Therefore, the absolute value of the correlation coefficient indicates the strength of relationship, with closer to 1 indicating a stronger relationship. Of the options given, -.75 has the strongest relationship, as it is closest to -1.

Question 2

As a project for a psychology course, a student correlated weight and intelligence scores for 250 students. The computed correlation coefficient was .00. What did the scatter plot look like?
A) a random distribution of points
B) a line with a positive slope.
C) a straight line from the lower left to the upper right-hand corner
D) a straight line from the upper left to the lower right-hand corner

Accepted Answer

The correlation coefficient of 0.00 indicates no linear relationship between weight and intelligence scores. This means that the scatter plot would show a random distribution of points, with no clear pattern or trend.

Question 3

Why is it important to make sure that different participant groups are roughly equivalent in terms of personal characteristics (e.g., age, gender) before any independent variable is introduced?
A) Because it is important to treat all research participants equally so that they feel that they are not being manipulated.
B) Because research ethics forbid any experiment to take place when the participant groups are fundamentally different from each other.
C) So that no major differences between the groups unduly bias the results of the experiment.
D) Because it threatens the integrity of a within-group experimental design.

Accepted Answer

The answer of Why is it important to make sure...

Question 4

Julie finds that the number of hours she sleeps each night is related to the scores she receives on quizzes the next day. As her sleep approaches 8 hours, her quiz scores improve; as her sleep drops to 5 hours, her quiz scores show a similar decline. Julie realizes that ______________________.
A) there is a negative correlation between the number of hours she sleeps and her quiz grades
B) there is a positive correlation between the number of hours she sleeps and her quiz grades
C) her low quiz scores are caused by sleep deprivation the night before a quiz
D) she should sleep about 10 hours a night to ensure 100 percent quiz grades

Accepted Answer

The statement "As her sleep approaches 8 hours, her quiz scores improve; as her sleep drops to 5 hours, her quiz scores show a similar decline" suggests a positive correlation between the number of hours she sleeps and her quiz grades. A negative correlation would mean that as the number of hours she sleeps decreases, her quiz scores increase, which is not the case. The information given does not support option C or D as the cause of her low quiz scores or the amount of sleep required for perfect quiz grades is not stated.

Question 5

A correlation coefficient is a numerical measure of the __________________.
A) unintended changes in participants' behavior due to cues from the experimenter
B) relationship between two variables
C) behaviors of participants of different ages compared at a given time
D) behaviors of participants followed and periodically assessed over time

Accepted Answer

A correlation coefficient is a statistical measure that indicates the strength and direction of the linear relationship between two variables. It is calculated based on the covariance between the variables divided by the product of their standard deviations. The resulting value ranges from -1 to 1, where values closer to -1 indicate a strong negative correlation, values closer to 1 indicate a strong positive correlation, and values close to 0 indicate no correlation between the variables. Therefore, the correct answer is B, which states that a correlation coefficient is a numerical measure of the relationship between two variables.

Question 6

In order to increase typing speed, Minisoft has redesigned its keyboard and provided a chime that is related to typing speed. The company wants to know if its innovations affect typing speed. Identify the independent and dependent variables in this proposed study.
A) The dependent variable is the chime; the independent variables are the chime and typing speed.
B) The dependent variable is speed of typing; the independent variables are the keyboard design and the chime.
C) The dependent variable is keyboard design; the independent variables are the speed of typing and the chime.
D) The dependent variable is the number of errors made; the independent variables are the chime and the speed of typing.

Accepted Answer

The dependent variable is the speed of typing, which is what is being measured and potentially affected by the keyboard design and chime. Therefore, the independent variables are the keyboard design and the chime.

Question 7

Which of the following statements is correct concerning correlation coefficients?
A) A correlation of +.89 is strong and -.89 is weak.
B) A correlation of +.89 and -.89 are both strong and equally so.
C) Correlation coefficients are indicators of cause and effect.
D) A correlation of +1.5 is very strong.

Accepted Answer

Correlation coefficients range from -1 to +1. A correlation coefficient of +1 indicates a perfect positive correlation, while a correlation coefficient of -1 indicates a perfect negative correlation. A correlation coefficient of 0 indicates no correlation at all. Therefore, a correlation of +.89 and -.89 are both strong and equally so, as they are close to the perfect correlation value of +1 or -1. However, it's important to note that correlation does not necessarily indicate causation. Also, a correlation coefficient cannot exceed 1 or -1, so a correlation of +1.5 is not possible.

Question 8

Drinking orange juice is negatively correlated with the risk of cancer. Based on this information, which of the following statements is true?
A) The more orange juice you drink, the higher your risk of cancer.
B) The more orange juice you drink, the lower your risk of cancer.
C) The less orange juice you drink, the lower your risk of cancer.
D) Drinking orange juice causes people to be cancer free.

Accepted Answer

Negative correlation means that as one variable increases, the other variable decreases. In this case, as the intake of orange juice increases, the risk of cancer decreases. Therefore, the more orange juice you drink, the lower your risk of cancer.

Question 9

Ken is planning on studying the influence of intelligence on the ability to recall events from the 1960s. If Ken does not account for variables such as age that could also influence one's ability to recall these events, age could be considered a(n) __________________.
A) random variable
B) dependent variable
C) confounding variable
D) independent variable

Accepted Answer

A confounding variable is a variable that is not the primary variable of interest, but can affect the relationship between the independent and dependent variables. In this case, age could affect one's ability to recall events from the 1960s, making it a confounding variable if not accounted for.

Question 10

A(n) is a measure of how strongly two variables are related to one another.
A) independent variable
B) dependent variable
C) experimental effect
D) correlation

Accepted Answer

Correlation is a measure of the strength and direction of the relationship between two variables. It is often measured by a correlation coefficient, which ranges from -1 to +1, with higher absolute values indicating stronger relationships. The variables are not necessarily causally related, but they may be associated in some way.

Question 11

Professor Holden gives a psychology exam on the origins of intelligence. She gives a short answer question based on the IQ scores of a parent-child pair. In order to answer the question correctly, her students need to remember that ________________.
A) a parent's high IQ does not necessarily cause a child to have a high IQ
B) given these variables, the correlation will be positive
C) given these variables, the correlation will be negative
D) given these variables, the correlation will be uncorrelated

Accepted Answer

While there may be some correlation between a parent's IQ and their child's IQ, it is not a guarantee that the child will have a high IQ based solely on their parents. Many other factors, such as environment and upbringing, can also play a role in a child's intelligence. Therefore, choice A is the best answer as it accurately reflects this concept. Choices B, C, and D are incorrect as they make assumptions or provide incorrect information about the relationship between parent and child IQ scores.

Question 12

A researcher is investigating the effects of exercise on weight. What are the independent and dependent variables in this experiment?
A) The dependent variable is weight; the independent variable is exercise.
B) The independent variable is calories consumed; the dependent variable is diet.
C) The independent variable is weight; the dependent variable is calories consumed.
D) The dependent variable is amount of exercise; the independent variable is calories consumed.

Accepted Answer

In this experiment, the independent variable is exercise, as this is the variable that is being manipulated by the researcher. The dependent variable is weight, as this is the variable that is being measured and is expected to be influenced by the independent variable of exercise. Therefore, choice A is the correct answer.

Question 13

Dr. Proverse has individuals cycle on stationary bikes for 0, 10, 20, or 30 minutes after which he measures their self-reported mood. In this hypothetical study, the dependent variable is _____________.
A) the self-reported mood
B) the individuals who do not ride on the stationary bike
C) the number of minutes individuals ride the bike
D) the riding of bikes

Accepted Answer

The dependent variable in this hypothetical study is the mood of the individuals which is being measured after cycling on stationary bikes for different amounts of time.

Question 14

Which correlation coefficient is most likely to describe the relationship between brushing one's teeth and the number of cavities one gets?
A) -.62
B) .83
C) -.08
D) .45

Accepted Answer

A negative correlation coefficient, such as -.62, indicates that as one variable increases, the other decreases. In this context, as the frequency of brushing one's teeth increases (assuming proper technique and duration), the number of cavities is likely to decrease, which is consistent with the expected relationship between these variables.

Question 15

Independent variable is to dependent variable as ________.
A) effect is to confound
B) experimental is to correlation
C) measure is to manipulate
D) manipulate is to measure

Accepted Answer

In an experiment, the independent variable is the one that is manipulated by the researcher, while the dependent variable is the one that is measured to see how it is affected by changes in the independent variable.

Question 16

Ideally, everything in the experimental situation except the __________________ is held constant.
A) inferential statistics
B) placebos
C) independent variables
D) hypotheses

Accepted Answer

The independent variable is the variable being manipulated or changed in the experiment, therefore everything else should be held constant to accurately assess the effect of the independent variable. Placebos may be used to control for the placebo effect, and inferential statistics may be used to analyze the data, but they are not the main focus of keeping everything else constant. Hypotheses are proposed before the experiment and are not related to keeping everything else constant during the experimental situation.

Question 17

A good control group ________.
A) contains at least one confound
B) has a limited number of dependent variables
C) has a limited number of research participants
D) holds constant all variables in the experiment

Accepted Answer

A good control group holds constant all variables in the experiment to isolate the effect of the independent variable on the dependent variable. This ensures that any observed differences between the control group and the experimental group can be attributed to the independent variable, rather than other variables. A control group should not contain any confounds, and can have any number of dependent variables or research participants.

Question 18

Paul records data that indicate that the number of hot chocolates sold at the concession stand increases as temperature outside decreases (for example, more hot chocolates are purchased during late fall than late spring). Which of the following statements is the most accurate depiction of this finding?
A) There is a correlation between the two variables.
B) There is a strong, positive correlation between the two variables.
C) There is a weak, positive correlation between the two variables.
D) There is a negative correlation between the two variables.

Accepted Answer

The answer of Paul records data that indicate that the...

Question 19

Dr. Keller has individuals run on a treadmill for 0, 15, or 30 minutes and then measures their self-reported mood. In this hypothetical study, the independent variable is
A) the self-reported mood.
B) the individuals who run for 15 or 30 minutes.
C) the individuals who run for 0 minutes.
D) the number of minutes individuals run on the treadmill.

Accepted Answer

The independent variable is the factor that is manipulated or varied by the researcher to measure its effect on the dependent variable, which in this study is self-reported mood. In this case, the independent variable is the number of minutes individuals run on the treadmill (0, 15, or 30 minutes). Therefore, the best choice is D. Choices A, B, and C are incorrect as they refer to either the dependent variable (self-reported mood) or a subset of the independent variable (individuals who run for 15 or 30 minutes or 0 minutes).

Question 20

A variable that the experimenter manipulates is called a(n) _____________.
A) coefficient of correlation
B) dependent variable
C) control condition
D) independent variable

Accepted Answer

The independent variable is the variable that the experimenter manipulates or changes. It is typically used to test the effect of one variable on another, which is known as the dependent variable. The other options (A, B, and C) do not accurately describe the variable being manipulated in the experiment.

Quiz 1: Introduction to the Science of Psychology: History and Research Methods

Which of the following correlation coefficients represents the strongest relationship between two variables?

As a project for a psychology course, a student correlated weight and intelligence scores for 250 students. The computed correlation coefficient was .00. What did the scatter plot look like?

Why is it important to make sure that different participant groups are roughly equivalent in terms of personal characteristics (e.g., age, gender) before any independent variable is introduced?

Julie finds that the number of hours she sleeps each night is related to the scores she receives on quizzes the next day. As her sleep approaches 8 hours, her quiz scores improve; as her sleep drops to 5 hours, her quiz scores show a similar decline. Julie realizes that ______________________.

A correlation coefficient is a numerical measure of the __________________.

In order to increase typing speed, Minisoft has redesigned its keyboard and provided a chime that is related to typing speed. The company wants to know if its innovations affect typing speed. Identify the independent and dependent variables in this proposed study.

Which of the following statements is correct concerning correlation coefficients?

Drinking orange juice is negatively correlated with the risk of cancer. Based on this information, which of the following statements is true?

Ken is planning on studying the influence of intelligence on the ability to recall events from the 1960s. If Ken does not account for variables such as age that could also influence one's ability to recall these events, age could be considered a(n) __________________.

A(n) is a measure of how strongly two variables are related to one another.

Professor Holden gives a psychology exam on the origins of intelligence. She gives a short answer question based on the IQ scores of a parent-child pair. In order to answer the question correctly, her students need to remember that ________________.

A researcher is investigating the effects of exercise on weight. What are the independent and dependent variables in this experiment?

Dr. Proverse has individuals cycle on stationary bikes for 0, 10, 20, or 30 minutes after which he measures their self-reported mood. In this hypothetical study, the dependent variable is _____________.

Which correlation coefficient is most likely to describe the relationship between brushing one's teeth and the number of cavities one gets?

Independent variable is to dependent variable as ________.

Ideally, everything in the experimental situation except the __________________ is held constant.

A good control group ________.

Dr. Keller has individuals run on a treadmill for 0, 15, or 30 minutes and then measures their self-reported mood. In this hypothetical study, the independent variable is

A variable that the experimenter manipulates is called a(n) _____________.