Question 1

What does the first of the "W's," "What," refer to?
A) topic of study
B) location
C) time period
D) type of case

Accepted Answer

The first "W," "What," refers to the topic of study, indicating the subject or area being investigated or discussed.

Question 2

What does the honorary W, "How", refer to?
A) time period of study
B) interpreting results
C) study design and methods
D) location of study

Accepted Answer

The honorary W, "How", refers to the study design and methods, indicating the approach or methodology used to conduct the study.

Question 3

A researcher is conducting a study on the inventory needed by rental car agencies to meet daily demand for car types. In her study design, she decides on a sample of three car rental agencies for inclusion in the study. Which W or honorary W does this sampling task represent?
A) how
B) how many
C) what
D) where

Accepted Answer

The sampling task represents "how many" because it involves deciding on the number of car rental agencies to include in the study.

Question 4

What does "substantive significance" mean in the context of research?
A) significance level of a test
B) validity of a sample
C) p value of a significance test
D) practical importance of a result

Accepted Answer

Substantive significance refers to the practical importance or real-world relevance of a research finding, beyond just statistical significance. It addresses whether the size of an effect or the difference observed in the study is large enough to be considered meaningful in a practical sense.

Question 5

What does a p value measure?
A) probability of wrongly concluding the true parameter is 0
B) the significance level of a research test
C) probability of the alternative hypothesis being true
D) the correlation between two levels

Accepted Answer

A p-value measures the probability of observing the data, or something more extreme, if the null hypothesis is true. It does not directly measure the probability of the alternative hypothesis being true or the correlation between levels.

Question 6

Which of the following cannot be confirmed by a statistical significance test?
A) accept the null hypothesis
B) cause and effect relationship
C) population parameter is nonzero
D) reject the alternative hypothesis

Accepted Answer

A statistical significance test can only confirm whether there is a statistically significant difference between two groups or whether a population parameter is different from zero. It cannot establish a cause-and-effect relationship.

Question 7

In which of the following cases, should statistical significance of an association not be the reason for an intervention?
A) the dependent variable is modifiable
B) the size of the association is large
C) direction of association is known
D) the independent variable cannot be modified

Accepted Answer

Statistical significance does not necessarily imply practical significance, especially when the independent variable cannot be modified. In such cases, even if an association is statistically significant, it may not be actionable or relevant for intervention.

Question 8

Which of the following lists the dimensions of "importance" of a research result?
A) statistical significance and substantive significance
B) practical importance, statistical significance, internal and external validity
C) measurement level, causality, and practical importance
D) benchmarks, measurement level, internal validity, and central tendency

Accepted Answer

B) is correct because it encompasses a broad range of dimensions that are crucial for assessing the importance of a research result. Practical importance refers to the real-world relevance or impact of the findings. Statistical significance assesses whether the observed effects are likely to be due to chance. Internal validity concerns the extent to which the study accurately establishes cause-and-effect relationships within its context, while external validity relates to the generalizability of the findings to other contexts or populations.

Question 9

What criteria is used to assess the practical importance of a research result?
A) confidence limits
B) mechanism
C) effect size
D) p value

Accepted Answer

Effect size is used to assess the practical importance of a research result because it quantifies the size of the difference between groups or the strength of a relationship, providing a measure of the magnitude of the effect that is independent of sample size.

Question 10

Which of the following criteria is used to assess the internal validity of a research result?
A) empirical association
B) effect size
C) p value
D) measurement value

Accepted Answer

Internal validity refers to the extent to which a study can establish a causal relationship between variables. Empirical association is a criterion for establishing causality, thus relevant to internal validity.

Question 11

A regression analysis was conducted with dependent variable A and independent variables B and C. The regression coefficients fell within confidence intervals that did not equal 0. Moreover, the coefficients had p values less than 0.0001. Which dimension of "importance" do these results satisfy?
A) cause-and-effect
B) statistical significance
C) benchmarking
D) effect size

Accepted Answer

The results indicate statistical significance because the p-values are less than 0.0001, suggesting that the findings are unlikely to have occurred by chance. The confidence intervals not equaling 0 further supports this.

Question 12

What factor(s) does the criteria "empirical association" depend on in a research study?
A) cross-sectional study design
B) experimental study design
C) consistency of direction and size
D) sampling method

Accepted Answer

Empirical association in research refers to the consistent relationship between variables, which is indicated by the consistency of direction and size of the observed effects, rather than the specific study design or sampling method used.

Question 13

What does the criteria "Nonspuriousness" refer to, in checking for internal validity of a research result?
A) a random sample using probability methods
B) a p value less than .05 for a coefficient
C) separate multiple topics into different studies
D) true association after accounting for confounders

Accepted Answer

Nonspuriousness refers to ensuring that the observed association between variables is genuine and not due to some other variable (confounder). This means that the relationship remains true even after accounting for potential confounding factors.

Question 14

In a research study, a random sample was taken of a binary dependent variable and three independent variables hypothesized to be associated with the dependent variable. A statistical model was developed on the sample data, and the model was then applied to a validation sample. The results of the model were checked to see if the variable distributions were similar to the population from which the samples were taken. This check is related to which dimension of determining importance of results?
A) measurement level
B) external validity
C) internal validity
D) statistical significance

Accepted Answer

The check to see if the variable distributions in the sample are similar to those in the population is related to external validity. External validity refers to the extent to which the results of a study can be generalized to other situations and to other people. By ensuring that the sample distributions match the population, researchers aim to enhance the generalizability of their findings.

Question 15

In determining practical importance of a result, which measure is referred to, along with effect size?
A) variation
B) mean
C) standard error
D) confidence level

Accepted Answer

Variation is often considered alongside effect size to determine the practical importance of a result, as it provides context on the spread of data and the consistency of the effect.

Question 16

How is the sample size related to the measure of spread in a research study?
A) weakly related
B) positively related
C) inversely related
D) not related

Accepted Answer

The sample size is inversely related to the measure of spread in a research study because as the sample size increases, the variability or spread of the data tends to decrease, leading to more precise estimates of population parameters.

Question 17

What is the relationship between sample size and width of confidence intervals?
A) inversely related
B) not related
C) positively related
D) weakly related

Accepted Answer

Larger sample sizes lead to narrower confidence intervals, indicating an inverse relationship between sample size and the width of confidence intervals. This is because larger samples provide more information about the population, reducing uncertainty.

Question 18

An empirical association is shown to be stronger due to which of the following factor(s)?
A) wider confidence limits
B) larger effect sizes and smaller p values
C) larger measures of dispersion
D) smaller margin of error and confidence level

Accepted Answer

Larger effect sizes and smaller p values indicate a stronger empirical association because they suggest that the observed effect is not likely due to chance, making the association between variables more convincing.

Question 19

In addition to empirical association, what are the two other criteria needed to assess a cause-and-effect relationship between a dependent and an independent variable?
A) measurement level and p value
B) effect size and value
C) confidence limits and standard error
D) mechanism and nonspuriousness

Accepted Answer

Mechanism and nonspuriousness are essential criteria for establishing a cause-and-effect relationship. A mechanism explains how the independent variable affects the dependent variable, while nonspuriousness ensures that the observed relationship is not due to some other variable.

Question 20

A study on median house prices in Middlesex county used a random sample of 200 houses from three zip codes of the county. Which dimension of 'importance' of study results would this sampling affect? Choose the best answer.
A) internal validity
B) statistical significance
C) external validity
D) practical importance

Accepted Answer

External validity refers to the extent to which the results of a study can be generalized or applied to other settings, populations, or situations. By sampling houses from only three zip codes in Middlesex county, the study's findings may not be generalizable to the entire county or to other regions, affecting the study's external validity.

Quiz 15: The Role of Research Methods in Making Sense of Numbers

What does the first of the "W's," "What," refer to?

What does the honorary W, "How", refer to?

A researcher is conducting a study on the inventory needed by rental car agencies to meet daily demand for car types. In her study design, she decides on a sample of three car rental agencies for inclusion in the study. Which W or honorary W does this sampling task represent?

What does "substantive significance" mean in the context of research?

What does a p value measure?

Which of the following cannot be confirmed by a statistical significance test?

In which of the following cases, should statistical significance of an association not be the reason for an intervention?

Which of the following lists the dimensions of "importance" of a research result?

What criteria is used to assess the practical importance of a research result?

Which of the following criteria is used to assess the internal validity of a research result?

A regression analysis was conducted with dependent variable A and independent variables B and C. The regression coefficients fell within confidence intervals that did not equal 0. Moreover, the coefficients had p values less than 0.0001. Which dimension of "importance" do these results satisfy?

What factor(s) does the criteria "empirical association" depend on in a research study?

What does the criteria "Nonspuriousness" refer to, in checking for internal validity of a research result?

In determining practical importance of a result, which measure is referred to, along with effect size?

How is the sample size related to the measure of spread in a research study?

What is the relationship between sample size and width of confidence intervals?

An empirical association is shown to be stronger due to which of the following factor(s) ?

In addition to empirical association, what are the two other criteria needed to assess a cause-and-effect relationship between a dependent and an independent variable?

A study on median house prices in Middlesex county used a random sample of 200 houses from three zip codes of the county. Which dimension of 'importance' of study results would this sampling affect? Choose the best answer.