Question 1

The Pearson correlation is used when both scores are _____.

Accepted Answer

The Pearson correlation is used to measure the degree of linear relationship between two variables that are measured on either an interval or ratio scale. Therefore, the best choice is C.

Question 2

A researcher conducts a survey examining eating and sleeping behavior as well as academic performance for a group of elementary school children. The results of the survey indicate that the children who eat a more nutritious breakfast tend to have better grades than the children who have a breakfast low in nutrition. However, the research suspects that the children's parents may be responsible for this relationship. Specifically, the better-educated parents probably encourage their children to eat better food and work harder in school compared to parents with less education. If the researcher is correct, this is an example of the ____.

Accepted Answer

The third-variable problem occurs when a third variable, such as parents' education level, may be responsible for the relationship observed between two other variables, in this case, breakfast nutrition and academic performance. The directionality problem occurs when the direction of cause-and-effect cannot be determined. The reversal problem occurs when the cause-and-effect relationship may actually be the opposite of what is expected. The criterion problem pertains to issues surrounding how variables are measured or defined.

Question 3

A Pearson correlation of r = +0.9 indicates that a graph of the data would show points ____.

Accepted Answer

A Pearson correlation coefficient of +0.9 indicates a strong positive correlation between two variables. This means that as one variable increases, the other variable also tends to increase. When graphing the data, the points would be clustered close to a line that slopes up to the right.

Question 4

Which correlation is appropriate for measuring the relationship between gender (male/female) and performance on a task (success/failure)?

Accepted Answer

The phi-coefficient is appropriate for measuring the relationship between two binary variables, such as gender (male/female) and task performance (success/failure).

Question 5

The results from a correlational study show a positive relationship between aggressive behavior for six-year-old children and the amount of violence they watch on television. Based on this relationship, which of the following conclusions is justified?

Accepted Answer

This conclusion is justified based on the positive relationship found in the correlational study. It suggests that there is a tendency for children who watch more TV violence to exhibit more aggressive behavior, but it does not necessarily mean that decreasing or increasing the amount of violence they see on TV will have a direct causal effect on their behavior. Additionally, the study does not provide evidence to support choices A, B, or D.

Question 6

For a correlational study in which participants are scored as "high," "medium," and "low" on both variables, which correlation is designed to measure the consistency of the relationship?

Accepted Answer

A Spearman correlation is designed to measure the consistency of the relationship between two variables that have been scored as ordinal data, like "high," "medium," and "low." It measures the degree to which the two variables are related linearly.

Question 7

If one score in a correlational study is numerical and the other is non-numerical, the non-numerical variable can be used to organize the scores into separate groups which can then be compared with a _____.

Accepted Answer

A t-test is appropriate for comparing the means of two groups when one variable is numerical and the other is non-numerical, allowing the non-numerical variable to categorize the data into two groups.

Question 8

Which set of correlations correctly shows the highest to lowest degree of relationship?

Accepted Answer

Correlation coefficients range from -1 to +1, where values closer to +1 or -1 indicate a stronger relationship, and values closer to 0 indicate a weaker relationship. The order from highest to lowest degree of relationship, regardless of the sign, is: −0.91, +0.83, +0.10, −0.03.

Question 9

When a person applies to rent a house, he/she sometimes is required to consent to a credit check along with his/her application. Landlords know that there is a relationship between credit score and likelihood of paying rent on time. In this situation, paying rent on time is best characterized as the ____ variable.

Accepted Answer

The best choice is criterion because it is the variable that is being predicted or measured, in this case, the likelihood of paying rent on time. The credit score would be the predictor variable as it is being used to predict the criterion variable. The terms "dependent" and "independent" refer to the relationship between two variables, with the dependent variable being affected by the independent variable, and this terminology does not accurately capture the relationship between credit score and paying rent on time.

Question 10

A scatter plot shows a set of data points that are clustered close to a line that slopes down to the right. Which value would be closest to the correlation for these data?

Accepted Answer

A line that slopes down to the right indicates a negative correlation. Of the options given, the closest value to a negative correlation would be -0.80.

Question 11

What is indicated by a negative correlation between grade point average and the number of hours spent studying for a sample of college students?

Accepted Answer

A negative correlation indicates that as one variable (number of hours spent studying) increases, the other variable (grade point average) decreases. Therefore, Choice B is the correct answer.

Question 12

A statistically significant correlation means that ____.

Accepted Answer

A statistically significant correlation means that there is a real relationship between the variables. It does not necessarily indicate the size of the correlation, but rather that it is unlikely to occur by chance.

Question 13

Dr. Jones hopes to demonstrate that children who eat a more nutritious breakfast also tend to have more academic success than their peers. If this result is obtained, then ____ would be the predictor variable and ____ would be the criterion variable for the study.

Accepted Answer

In this study, the predictor variable is what is being manipulated or measured, which is the nutrition in the breakfast. The criterion variable is the outcome being observed or measured based on the predictor variable, which is the level of academic success. Therefore, the correct choice is A where the predictor variable is the nutrition in the breakfast and the criterion variable is the level of success.

Question 14

A researcher reports a positive relationship between sugar consumption and activity level for a group of eight-year-old children. However, the researcher cannot be sure whether the extra sugar is causing the children to be more active or whether the extra activity is causing the children to eat more sugar. This is an example of the ____.

Accepted Answer

The scenario describes a situation where it is unclear which variable is causing the other, which is known as the directionality problem. The third-variable problem refers to a situation where there is a third variable that is influencing both variables being studied, the reversal problem refers to when the causality may go in either direction, and the criterion problem refers to issues with defining and measuring variables.

Question 15

Regression is the statistical process for _____.

Accepted Answer

Regression involves using one variable (the predictor variable) to predict another variable (the outcome variable). It is used for making predictions or estimating the value of an outcome variable based on the value of one or more predictor variables.

Question 16

The coefficient of determination is ____.

Accepted Answer

The coefficient of determination is computed by squaring the correlation coefficient. It represents the proportion of the variance in one variable that can be explained by the other variable. Therefore, it ranges between 0 and 1, with 1 indicating a perfect relationship and 0 indicating no relationship.

Question 17

To establish the concurrent validity of a measure, of academic motivation a researcher examines the ____.

Accepted Answer

To establish concurrent validity of a measure, a researcher examines the relationship between the measure and another well-established measure, which assesses the same construct. This approach helps to establish whether the new measure is measuring what it is intended to measure and how it compares to an already established and commonly accepted measure of the construct. Option A is incorrect because it describes test-retest reliability rather than concurrent validity. Options C and D are also incorrect as they describe mean differences rather than the relationship between measures.

Question 18

To establish the test-retest reliability of a measure of academic motivation, a researcher examines the ____.

Accepted Answer

Test-retest reliability refers to the consistency of scores over time. Therefore, the researcher would need to examine the relationship between scores from two administrations of the measure to establish test-retest reliability. Option B refers to concurrent validity, option C refers to measures of central tendency, and option D refers to convergent validity.

Question 19

The correlational research strategy is often used to establish the ________ of a measurement by demonstrating that the scores from the study's test are strongly related to the scores from established tests.

Accepted Answer

The correlational research strategy is often used to establish the concurrent validity of a measurement by demonstrating that the scores from the study's test are strongly related to the scores from established tests. Concurrent validity refers to the degree to which the scores on a new measure are related to scores on a criterion measure administered at the same time.

Question 20

The Spearman correlation is used when both scores are _____.

Accepted Answer

The Spearman correlation is used when both scores are from the ordinal scale, which is a type of categorical data where values can be ranked in order but the distance between the values is not necessarily equal. It is a non-parametric measure of correlation that assesses how well the relationship between two variables can be described using a monotonic function, which means that as one variable increases, the other variable either increases or decreases in a consistent manner, but not necessarily at a constant rate. The Spearman correlation coefficient can take values between -1 and 1, with 0 indicating no correlation and values closer to -1 or 1 indicating stronger correlation.

Quiz 12: The Correlational Research Strategy