Question 1

Which of the following best characterizes the findings of Downey's study of the effect of family size on grades?
A) Children from large families get slightly better grades than children from smaller families.
B) Children from smaller families get slightly better grades than children from larger families.
C) Children from smaller families get much better grades than children from larger families.
D) Children from smaller families and children from larger families get the same grades.

Accepted Answer

Downey's study found that children from smaller families tend to have slightly better grades than children from larger families.

Question 2

In a typical SPSS regression, how many boxes of output are involved?
A) 2
B) 4
C) 6
D) 8

Accepted Answer

The answer of In a typical SPSS regression, how many...

Question 3

For which the following scenarios is the Adjusted r-squared most likely to differ from the regular r-squared?
A) When the sample size is small and the number of independent variables is large
B) When the sample size is large and the number of independent variables is large
C) When the sample size is small and the number of independent variables is small
D) When the sample size is large and the number of independent variables is small

Accepted Answer

When the sample size is small and the number of independent variables is large, the regular r-squared tends to overestimate the true relationship between the dependent and independent variables. The Adjusted r-squared takes into account the number of independent variables and the sample size, therefore, it is more likely to differ from the regular r-squared in this scenario.

Question 4

In SPSS regression output, Sum of Squares Regression is the equivalent to:
A) the total amount of explained variation
B) the total amount of unexplained variation
C) the total amount of variation
D) the total amount of residual variation

Accepted Answer

Sum of Squares Regression represents the total amount of variation in the dependent variable (Y) that can be explained by the independent variable(s) (X), thus it is the total amount of explained variation.

Question 5

In SPSS regression output, Sum of Squares Residual is the equivalent to:
A) the total amount of explained variation
B) the total amount of unexplained variation
C) the total amount of variation
D) the total amount of residual variation

Accepted Answer

Sum of Squares Residual represents the total amount of unexplained variation in the regression model, which is the variation that is not accounted for by the independent variables.

Question 6

Someone collects data from your statistics class, runs a regression, and then presents the results, claiming that there is a statistical significant relationship between the percentage of classes you attend and your grade point average. Critique this person's finding.

Accepted Answer

The answer of Someone collects data from your statistics class,...

Question 7

Use the following GSS2008 results to explain how a slope could be statistically significant, yet substantively insignificant:
TVHOURS = 1.86 + .02 (AGE); Significance of slope: p<.001

Accepted Answer

The answer of Use the following GSS2008 results to explain...

Question 8

Here are data from the 16 American Indians in the GSS2008:
Independent Variable: Respondent's Father's Years of Education
Dependent Variable: Respondent's Years of Education
Standard Deviation of Independent Variable: 3.18
Standard Deviation of Dependent Variable: 2.50
Value of slope: .33
Value of r-squared: .18
Sample size: 16
Can we confidently claim that there is a relationship in the population of American Indians?

Accepted Answer

The answer of Here are data from the 16 American...

Question 9

Here are data from the 39 Hispanic women in the GSS2008:
Independent Variable: Woman's Number of Siblings
Dependent Variable: Women's Number of Children
Standard Deviation of Independent Variable: 3.24
Standard Deviation of Dependent Variable: 1.38
Value of slope: .16
Value of r-squared: .14
Sample size: 39
Can we confidently claim that there is a relationship in the population of Hispanic women between number of siblings and number of children?

Accepted Answer

The answer of Here are data from the 39 Hispanic...

Question 10

A researcher runs a regression equation and finds the slope to be significant at the p<.05 level. He then runs the same regression twice, once with the men in the sample, once with the women in the sample. Although both of these new slopes are exactly the same as the original slope, neither of these new slopes is statistically significant. Explain what likely happened.

Accepted Answer

The answer of A researcher runs a regression equation and...

Question 11

Someone looks at their SPSS regression output, and it says that the significance of their slope is .000. They take this to mean that they can be 100% certain that their slope is statistically significant. Explain to them why they are incorrect in this assumption.

Accepted Answer

The answer of Someone looks at their SPSS regression output,...

Question 12

A general rule people follow with large samples is: if the slope is twice as large as the standard error of the slope, then the slope is statistically significant. Explain where this rule comes from.

Accepted Answer

The answer of A general rule people follow with large...

Question 13

A researcher takes a random sample of 10 people and calculates regression results, getting a p-value of 0.052: frustratingly close to statistical significance. To achieve statistical significance, the researcher takes a new, slightly larger sample of 15 people. She now gets a p-value of 0.087. Explain to the researcher what might have happened.

Accepted Answer

The answer of A researcher takes a random sample of...

Question 14

What is Ansell's major finding in his research on attitudes toward social security spending?

Accepted Answer

The answer of What is Ansell's major finding in his...

Question 15

Explain how the Downey article on family size and child's grades offers a contrast between statistical significance and substantive significance.

Accepted Answer

The answer of Explain how the Downey article on family...

Quiz 8: Using Sample Slopes to Talk About Populations: Inference and Regression

Which of the following best characterizes the findings of Downey's study of the effect of family size on grades?

In a typical SPSS regression, how many boxes of output are involved?

For which the following scenarios is the Adjusted r-squared most likely to differ from the regular r-squared?

In SPSS regression output, Sum of Squares Regression is the equivalent to:

In SPSS regression output, Sum of Squares Residual is the equivalent to:

Someone collects data from your statistics class, runs a regression, and then presents the results, claiming that there is a statistical significant relationship between the percentage of classes you attend and your grade point average. Critique this person's finding.

Use the following GSS2008 results to explain how a slope could be statistically significant, yet substantively insignificant: TVHOURS = 1.86 + .02 (AGE); Significance of slope: p<.001

Someone looks at their SPSS regression output, and it says that the significance of their slope is .000. They take this to mean that they can be 100% certain that their slope is statistically significant. Explain to them why they are incorrect in this assumption.

A general rule people follow with large samples is: if the slope is twice as large as the standard error of the slope, then the slope is statistically significant. Explain where this rule comes from.

What is Ansell's major finding in his research on attitudes toward social security spending?

Explain how the Downey article on family size and child's grades offers a contrast between statistical significance and substantive significance.