Chapter 8
When examining an association in which one variable is categorical and one is quantitative, which of the following is NOT likely to be used?
A scatterplot
RESEARCH STUDY 8.1: Dr. Guidry conducts a study examining the relationship between the number of friends one has and the experience of daily stress and life satisfaction. She randomly samples 1,500 elderly men and women in Nashville, Tennessee (the state capital), located in the southern United States. Below are her findings.• Life satisfaction and experience of daily stress: r = −.57 ( p = .01)• Number of friends one has and experience of daily stress: r = .09, not sig.• Number of friends one has and life satisfaction: r = .36 ( p = .04)In evaluating Dr. Guidry's study, you question the construct validity of the study. Which of the following questions would you be asking?
How reliable is the measure of daily stress?
Which of the following is true of the relationship between effect size and statistical significance?
Larger effect sizes are advantageous for statistical significance.
RESEARCH STUDY 8.1: Dr. Guidry conducts a study examining the relationship between the number of friends one has and the experience of daily stress and life satisfaction. She randomly samples 1,500 elderly men and women in Nashville, Tennessee (the state capital), located in the southern United States. Below are her findings.• Life satisfaction and experience of daily stress: r = −.57 ( p = .01)• Number of friends one has and experience of daily stress: r = .09, not sig.• Number of friends one has and life satisfaction: r = .36 ( p = .04)In determining whether the relationship between two of Dr. Guidry's variables was statistically significant, which of the following must be considered?
Sample size and effect size
If an association study did not select people for the study by using random sampling, which of the following statements is true?
The findings should be replicated in another population.
RESEARCH STUDY 8.1: Dr. Guidry conducts a study examining the relationship between the number of friends one has and the experience of daily stress and life satisfaction. She randomly samples 1,500 elderly men and women in Nashville, Tennessee (the state capital), located in the southern United States. Below are her findings.• Life satisfaction and experience of daily stress: r = −.57 ( p = .01)• Number of friends one has and experience of daily stress: r = .09, not sig.• Number of friends one has and life satisfaction: r = .36 ( p = .04)Which of the following conclusions can Dr. Guidry draw about the number of friends one has and life satisfaction based on her statistical analyses?
The probability of her sample coming from a zero association population is about 4%.
Which of the following questions is NOT necessary to ask when interrogating statistical validity? a. Could outliers be affecting the relationship? b. Is random assignment affecting the findings? c. What is the effect size? d. Are there subgroups?
b. Is random assignment affecting the findings?
Why are curvilinear relationships hard to detect with correlation coefficients ( r)?
r always looks for the best straight line to fit the data.
If there is not a full range of scores on one of the variables, this is known as _________.
restriction of range
The figure above is an example of a _________.
scatterplot
