Deck 12: Random Error

Question 1

Which of the following is considered unsystematic because it arises from an unforeseeable and unpredictable process?

A) Bias
B) Confounding
C) Random error
D) Generalization

Answer 1

Random error

Question 2

When investigators measure which rate in a particular population, random errors may occur during the process of identifying cases of disease or calculating person-time of follow-up?

A) Incidence rate
B) Prevalence rate
C) Morbidity rate
D) Mortality rate

Answer 2

Incidence rate

Question 3

Which of the following measures can be thought of as the lack of random error?

A) Validity
B) Reliability
C) Accuracy
D) Precision

Answer 3

Precision

Question 4

Which type of epidemiologist believes that random error, or chance, is an important, even chief, explanation for events?

A) Probablists
B) Determinists
C) Statisticians
D) Idealists

Question 5

When a P value is less than or equal to which value, we reject the null hypothesis in favor of the alternative because random error is an unlikely explanation of the discrepancy between the results and the null hypothesis?

A) 0.01
B) 0.05
C) 0.10
D) 0.50

Question 6

Which of the following is the middlemost observation of the distribution, that is, the observation in which 50% of the observations fall above it and 50% of the observations fall below it?

A) Mean
B) Median
C) Mode
D) Standard deviation

Question 7

Which type of distribution is frequently used in epidemiological research because many diseases are uncommon, particularly if one considers the likelihood of occurrence in a short period of time?

A) Normal distribution
B) Poisson distribution
C) Gaussian distribution
D) Binomial distribution

Question 8

A small P value means that the alternative hypothesis is a better explanation for the results than the null hypothesis.

Question 9

The statements "statistically significant" and "not statistically significant" indicate that the null hypothesis is true.

Question 10

Because the significance level is an arbitrary cutoff, it is possible to incorrectly reject or not reject the null hypothesis.

Question 11

Which of the following leads to a false association between the exposure and disease that arises from chance, an uncontrollable force that seems to have no assignable cause?

A) Bias
B) Confounding
C) Random error
D) Generalization

Question 12

During the third phase of biostatistical history, between World Wars I and II, R.A. Fisher developed theoretical models for which of the following, a method for generalizing results from a sample to a population?

A) Linear regression
B) Dose-response relationships
C) Agent-based modeling
D) Statistical inference

Question 13

Which group believes that all events are "predestined to unravel in a theoretically predictable way that follows inexorably from the previous pattern of actions"?

A) Probablists
B) Determinists
C) Statisticians
D) Idealists

Question 14

In which of the following is the parent population first divided into subgroups, then a random sample is selected from each subgroup?

A) Simple random sample
B) Nested random sample
C) Clustered random sample
D) Stratified random sample

Question 15

Which of the following is considered a "uniform decision-making criterion" for evaluating random error that is superior to subjective impressions of the data?

A) Hypothesis testing
B) Dose-response relationships
C) Agent-based modeling
D) Statistical inference

Question 16

Which of the following quantifies the compatibility of the study data with the null hypothesis?

A) P Value
B) Confidence interval
C) Odds ratio
D) Risk ratio

Question 17

The incorrect failure to reject a false null hypothesis is called which type of error?

A) Alpha error
B) Beta error
C) Random error
D) Measurement error

Question 18

Because random samples are uncommon in epidemiological research, many epidemiologists question the use of P-values and confidence intervals in observational studies.

Question 19

Statistical power measures the ability of a test to correctly reject the null hypothesis when the alternative hypothesis is true.

Question 20

P-values are confounded statistics because they simultaneously reflect the magnitude of the association and the study size.