Question 1

A third variable that is related to two other concepts/variables in a way that makes them appear to be related even in cases when they are not is called a(n)
A)inverse association.
B)exogenous variable.
C)interaction variable.
D)confounding variable.

Accepted Answer

A confounding variable is a third variable that can affect the relationship between two variables, making them appear to be related even when they are not. Confounding variables can lead to false conclusions in research. Therefore, the best answer is D, confounding variable.

Question 2

A body of research shows that people who have been divorced have a higher risk of divorce in any future marriage with another spouse.However,rather than divorce causing additional divorces,this seems to be more about other factors,such as how tolerant people are of divorce behavior.In this case,divorce attitudes would be a confounding factor because
A)more tolerant divorce attitudes are related both to first divorces and to later divorces.
B)people are almost never remarried to their ex-spouse,so the link is unlikely to be causal.
C)people's attitudes toward divorce may change after they've actually experienced it.
D)attitudes toward divorce may be related to first divorces,but not additional divorces.

Accepted Answer

A confounding factor is a variable that is not being studied but can affect the outcome of the study. In this case, divorce attitudes are a confounding factor because they are related to both first divorces and future divorces. People who have more tolerant attitudes towards divorce may be more likely to get divorced in the first place, and also more likely to divorce again in the future. Therefore, divorce attitudes need to be considered when studying the relationship between divorce and future marriages.

Question 3

A team of researchers is studying the possible effect of parents taking child-rearing classes on children's behavioral well-being.When they test the relevant null hypothesis,they are assessing whether
A)sample data show that child behavior differed by whether parents took the classes.
B)parenting classes are actually the independent variable rather than the dependent variable.
C)the observed association between parenting classes and child behavior is the result of chance.
D)the observed association is actually explained by a confounding variable.

Accepted Answer

Testing the null hypothesis involves determining whether the observed relationship between parenting classes and child behavior is statistically significant, or if it could be due to chance. The null hypothesis assumes that there is no true relationship between the variables (i.e. taking child-rearing classes does not affect children's behavioral well-being), and rejecting the null hypothesis would suggest that there is a significant relationship that is not likely due to chance.

Question 4

If an observed difference is statistically significant,but isn't large enough to be justifiably used to affect social policies,this difference is understood to lack
A)randomization.
B)elaboration.
C)statistical power.
D)practical significance.

Accepted Answer

Statistical significance refers to the likelihood that an observed difference is not due to chance. However, practical significance relates to whether the observed difference is large enough to make a meaningful impact or inform social policies. If the observed difference is statistically significant but lacks practical significance, it means that the effect size is too small to be considered important in practice. Therefore, the best choice is D, practical significance.

Question 5

If a study uses a p-value of 0.05 to determine statistical significance,the study's results only have a 1 in 20 chance of being due to random chance.If a researcher runs a large number of analyses,however,this increases the possibility that p-values
A)have no mathematical meaning with multiple analyses.
B)are at risk of being abused and selectively interpreted.
C)will be underestimated with smaller samples that require more analyses.
D)will be the same whether the sample is probabilistic or not.

Accepted Answer

When a researcher runs a large number of analyses, there is a higher risk of selectively interpreting only the statistically significant results, leading to an abuse of p-values. This can result in misleading conclusions and a lack of reproducibility of the results. Therefore, it is important to use appropriate multiple testing corrections and to interpret the results with caution.

Question 6

Arturo wants to use a probability sample to study the potential effects of health policies on infant mortality risk.To achieve this goal,the most important thing Arturo can do is to
A)use standardized questions in his survey.
B)get the largest sample he can acquire.
C)use randomization to select the sample.
D)only study populations with normally distributed mortality rates.

Accepted Answer

Randomization is crucial in probability sampling as it ensures that every member of the population has an equal chance of being selected for the sample. This helps to reduce bias and increase the representativeness of the sample. Using standardized questions and studying populations with normally distributed mortality rates may also be important, but they are not as crucial as using randomization to select the sample. Getting a larger sample may increase precision, but it is not the most important factor in achieving a representative sample.

Question 7

Ben has used a random sample of 20,000 respondents to test the relationship between participating in a summer reading program and children's reading scores in the following academic year.He observes a modest difference in reading scores by program participation and is able to reject the null hypothesis with a p-value of 0.04.When Ben presents his findings,his colleagues question whether the difference is very meaningful.Their concerns are most likely related to the fact that
A)his sample might not be representative of the population of children in schools.
B)he did not consider possible moderating variables.
C)his sample was so large that he was almost certain to find statistical significance.
D)a p-value is a very unreliable test for assessing statistical significance.

Accepted Answer

C) The concern likely stems from the fact that with a very large sample size, even very small differences can become statistically significant, which might not necessarily imply practical or meaningful differences.

Question 8

Bohai and Adal have administered a survey to a sample of college students to study the association between type of high school attended (public versus private)and social adjustment in college.They also considered the importance of students' socioeconomic background because that could affect the high school-college adjustment association.When all three variables are in the statistical model,the researchers observe a moderately larger adjustment score for students who attended public high schools,with a p-value of 0.03.These results tells Bohai and Adal that
A)there is only a small chance that the observed difference by high school is due to chance.
B)the null hypothesis can be rejected,but only for students who went to public high schools.
C)there is only a small chance that the sample is not representative of the college population.
D)socioeconomic background makes a 3% difference by high-school type.

Accepted Answer

A p-value of 0.03 indicates that there is only a small chance (3%) that the observed difference in adjustment score by high school is due to chance.

Question 9

Janae has examined sample data on a possible association between age and use of online coupons,comparing those who are 65 years or older to those 64 years of age or younger.She observes a 9% difference in online coupon use by age,such that those under 65 in her sample use coupons more than those who are 65 or older.She has a p-value of 0.08,which tells her that
A)younger people do use online coupons more,but that the difference is small.
B)she can reject the null hypothesis regarding age and online coupon use.
C)there is really an 8% age difference rather than a 9% difference.
D)there is an 8% chance that the observed age difference is due to chance.

Accepted Answer

The p-value of 0.08 indicates there is an 8% probability that the observed difference in online coupon use by age could have occurred by chance, not that the difference is exactly 8% or that the null hypothesis can be rejected.

Question 10

Two separate studies examine the potential association between occupation type and voter participation.The first advertises online for participants and asks those who respond to tell the researchers in-depth accounts regarding their paid work and their voting behaviors for the last three years.The second study randomly selects 200 respondents and asks them to complete a standardized set of survey questions about their paid work and voting behaviors over the past five years.The first study observes a patterned relationship between work and voting,while the second study does not.The reason the second study's results are more valid is that the
A)first study is based on experimental data,which are less reliable.
B)second study is based on a probability sample.
C)second study is based on more years of data on voting behaviors.
D)first study does not allow us to infer causality,but the second does.

Accepted Answer

The second study is based on a probability sample, which means that the respondents were randomly selected, increasing the likelihood that the results are representative of the larger population. The first study relies on participants self-selecting to respond to the advertisement, introducing potential biases in the sample. Therefore, the second study's results are more valid.

Question 11

Paloma has conducted a study on whether religious attendance is related to attitudes about legal gun control,using a nationally representative sample of 145 adults.She is surprised to find no association between the two variables.If there is actually a small correlation between religious attendance and gun control attitudes,one factor that is likely to have affected Paloma's findings is that
A)she only included adults in her sample instead of also including children and teens.
B)her sample size was not large enough to detect the difference by religious attendance.
C)religious attendance is too rare these days to be detected by national samples.
D)there is reciprocal causality that hides the basic association between the two variables.

Accepted Answer

A larger sample size would have increased the likelihood of detecting a small correlation between religious attendance and gun control attitudes. With a larger sample size, statistical power increases, allowing for more accurate estimates of the relationship between the two variables.

Question 12

A quantitative research project examines the relationship between unemployment rates and voter turnout.In this study,the researchers consider whether current public policies play a role in the unemployment-voter turnout connection.We can see this study is one that uses multivariate methods because it includes
A)both macro-and micro-level variables.
B)at least three variables.
C)at least two dependent variables.
D)longitudinal data.

Accepted Answer

Multivariate methods involve analyzing more than two variables to understand relationships or effects. In this study, at least three variables are considered: unemployment rates, voter turnout, and public policies, making it a multivariate analysis.

Question 13

Michelle is conducting research for her dissertation on whether birth order has an influence on how well high-school students perform on standardized tests.She has hypothesized that firstborn will perform better on average and has a long list of control variables she will test to make her study more informative.When Michelle tests for the main association between birth order and test scores,she finds a statistically significant relationship,but it is very small in magnitude.Her adviser suggests that she choose a different topic because
A)the finding does not have practical significance.
B)standardized test scores are so skewed that studies of them lack statistical power.
C)the null hypothesis cannot be rejected with sufficient confidence.
D)the importance of birth order is so varied across families.

Accepted Answer

The finding, while statistically significant, is very small in magnitude, which means that it may not have practical significance. In other words, the small effect found may not be meaningful enough to make any important changes to educational practices or policies. Therefore, choosing a different topic could be a more useful approach for Michelle's dissertation research.

Question 14

Which of the following would be an example of an inverse association?
A)Health and employment are related in a way that suggests reverse causality.
B)Fewer hours of sleep are associated with less weekly exercise.
C)More hours of weekly reading are associated with higher grades.
D)More education is associated with a lower likelihood of poverty.

Accepted Answer

An inverse association means that as one variable increases, the other decreases. In option D, more education is associated with a lower likelihood of poverty, indicating an inverse relationship.

Question 15

A researcher examines the possible effect of single-sex high-school education on men's college grades.He provides tables of his final results,which include several p-values that are less than 0.05,but he does not describe his many preliminary analyses,nor does he ever specify which high-school type he expects to predict higher grades among male college students.The scientific community is likely to have concerns over his interpretation of the p-values primarily because the researcher
A)does not hypothesize which high-school type should predict higher college grades.
B)does not also study the potential effect of single-sex schools for women.
C)was not transparent with the number and type of analyses he conducted.
D)does not study any measures of college outcomes other than grades.

Accepted Answer

The scientific community is likely to have concerns over the interpretation of the p-values primarily because the researcher was not transparent with the number and type of analyses he conducted. Without a clear understanding of the number and type of analyses conducted, it is difficult to determine if the p-values reported are valid or if they are simply the result of multiple comparisons. This lack of transparency can lead to questions about the validity of the researcher's findings.

Question 16

If certain values or responses on one variable tend to co-occur with certain values on another variable,we would interpret this as the existence of a(n)
A)association.
B)elaboration.
C)path diagram.
D)confounding.

Accepted Answer

The co-occurrence of certain values or responses on two variables indicates the presence of an association between the variables. This is a fundamental concept in statistics and social science research, as it can help us understand the relationships between different factors in a given phenomenon. Elaboration refers to the expansion or refinement of a particular concept or idea, and path diagrams are a visualization tool used in structural equation modeling. Confounding refers to the influence of external or unmeasured variables that can affect the relationship between two or more variables.

Question 17

A study finds a statistically significant association between divorce status and family attitudes,such that divorced people have more unconventional attitudes about family life.Which of the following would provide evidence of the statistical significance of this association?
A)that divorce had an effect on family attitudes that was at least a certain magnitude
B)a sufficient level of confidence that the observed association is not due to chance
C)that the association would be found across many different types of populations
D)evidence that divorce predicts family attitudes,but that attitudes do not predict divorce

Accepted Answer

A statistically significant association means that it is unlikely to have occurred by chance. Therefore, option B provides evidence of this statistical significance by stating that there is a sufficient level of confidence that the association is not due to chance. Options A, C, and D do not provide evidence specifically for the statistical significance of the association.

Question 18

The chance that at least some p-values will be lower than 0.05 increases when
A)the sample is nonprobabilistic.
B)the sample is smaller than 100 cases.
C)there is actually reverse causality.
D)the number of analyses gets higher.

Accepted Answer

When the number of analyses gets higher, the chance of finding at least some p-values lower than 0.05 increases, even if there is no true effect. This is known as the problem of multiple comparisons, and researchers need to correct for it to avoid false positive results.

Question 19

A city government has asked a research group to evaluate the effect of a new curfew ordinance on the number of monthly crimes.This curfew has reduced city revenue due to decreased commerce,and citizens are generally unhappy with it.While the curfew has already been instated,the city wants to use this study to decide whether to continue or discontinue the curfew.After six months,the study finds a statistically significant difference in the number of monthly crimes before and after the curfew was instated,but observes that the average number of monthly crimes over the six months only went down by 1.2 crimes with the curfew in place.When the researchers make their recommendation to the city based on this study,they should most likely recommend that the
A)study extend for one more year.
B)curfew be continued.
C)curfew be discontinued.
D)curfew be changed to one hour later.

Accepted Answer

While the study found a statistically significant difference in the number of crimes before and after the curfew was instated, the actual decrease in the average number of monthly crimes is quite small (only 1.2 crimes). Additionally, the curfew has reduced city revenue and citizens are not happy with it. Therefore, the researchers should most likely recommend that the curfew be discontinued. Extending the study for one more year may not significantly change the results, and changing the curfew time may not be necessary if the recommendation is to discontinue the curfew altogether.

Question 20

If a researcher hypothesizes that employment causes people to live longer,he or she may interpret an observed association between employment and number of years lived as evidence that supports his or her hypothesis.However,if adding healthiness to the model eliminates all of the original association between employment and number of years lived,this suggests that healthiness might predict both employment and longer life.This demonstrates that
A)reciprocal causality must always be considered for original hypotheses.
B)dependent variables must often be lagged for proper interpretation.
C)confounding factors present alternative explanations to original hypotheses.
D)adding new variables can change the results regarding the null hypothesis.

Accepted Answer

This scenario illustrates the possible influence of a confounding variable (healthiness) on the relationship between the independent variable (employment) and the dependent variable (number of years lived). The presence of such a variable can create alternative explanations for the initial hypothesis and must be considered in analyzing the results.

Quiz 15: Multivariate and Advanced Quantitative Methods

A third variable that is related to two other concepts/variables in a way that makes them appear to be related even in cases when they are not is called a(n)

A team of researchers is studying the possible effect of parents taking child-rearing classes on children's behavioral well-being.When they test the relevant null hypothesis,they are assessing whether

If an observed difference is statistically significant,but isn't large enough to be justifiably used to affect social policies,this difference is understood to lack

If a study uses a p-value of 0.05 to determine statistical significance,the study's results only have a 1 in 20 chance of being due to random chance.If a researcher runs a large number of analyses,however,this increases the possibility that p-values

Arturo wants to use a probability sample to study the potential effects of health policies on infant mortality risk.To achieve this goal,the most important thing Arturo can do is to

Which of the following would be an example of an inverse association?

If certain values or responses on one variable tend to co-occur with certain values on another variable,we would interpret this as the existence of a(n)

A study finds a statistically significant association between divorce status and family attitudes,such that divorced people have more unconventional attitudes about family life.Which of the following would provide evidence of the statistical significance of this association?

The chance that at least some p-values will be lower than 0.05 increases when