POPM*3240 Unit 02 Practice Questions
with Detailed Answers 2026/2027
Updated.
What is bias? (define bias) - Answer any systematic error in the design, conduct or analysis of a
study that results in a mistaken estimate of an exposure's effect on the risk of disease
Name the term that means "any systematic error in the design, conduct or analysis of a study
that results in a mistaken estimate of an exposure's effect on the risk of disease." - Answer
bias
True or False: "Random error is a type of bias." - Answer False, bias differs from random error
because it is systematic in nature
What is the difference between random error and bias? - Answer Random error is due to the
sample/ chance (random), whereas bias is systematic
True or False: "You can reduce bias by increasing sample size." - Answer False, simply
increasing the size of a sample will NOT address bias.
True or False: "You can reduce random error by increasing sample size." - Answer True
List the three main types of bias. - Answer 1. Selection
2. Information
3. Confounding
The following is the research process:
[Target population] ➡ [study sample] ➡ [data collection] ➡ [analysis]
Where in this process can *selection bias* occur?
(a) b/w [Target population] ➡ [study sample]
(b) b/w [study sample] ➡ [data collection]
(c) b/w [data collection] ➡ [analysis]
(d) before [Target population]
(e) after [analysis] - Answer (a) b/w [Target population] ➡ [study sample]
, The following is the research process:
[Target population] ➡ [study sample] ➡ [data collection] ➡ [analysis]
Where in this process can *information bias* occur?
(a) b/w [Target population] ➡ [study sample]
(b) b/w [study sample] ➡ [data collection]
(c) b/w [data collection] ➡ [analysis]
(d) before [Target population]
(e) after [analysis] - Answer (b) b/w [study sample] ➡ [data collection]
The following is the research process:
[Target population] ➡ [study sample] ➡ [data collection] ➡ [analysis]
Where in this process can *confounding* occur?
(a) b/w [Target population] ➡ [study sample]
(b) b/w [study sample] ➡ [data collection]
(c) b/w [data collection] ➡ [analysis]
(d) before [Target population]
(e) after [analysis] - Answer (c) b/w [data collection] ➡ [analysis]
True or False: "A causal pathway can be either direct or indirect." - Answer True
What is the difference between a *direct* causation and an *indirect* causation? - Answer A
*direct causation* indicates that a factor directly causes a disease or health outcome, without
any steps in between, while an *indirect causation* indicates that a factor causes disease, but
not before going through at least one intermediate step.
List the four types of factors when discussing types of causal relationships? - Answer ◾
Necessary and sufficient
◾ Necessary, but not sufficient
◾ Sufficient, but not necessary
◾ Neither necessary, nor sufficient
with Detailed Answers 2026/2027
Updated.
What is bias? (define bias) - Answer any systematic error in the design, conduct or analysis of a
study that results in a mistaken estimate of an exposure's effect on the risk of disease
Name the term that means "any systematic error in the design, conduct or analysis of a study
that results in a mistaken estimate of an exposure's effect on the risk of disease." - Answer
bias
True or False: "Random error is a type of bias." - Answer False, bias differs from random error
because it is systematic in nature
What is the difference between random error and bias? - Answer Random error is due to the
sample/ chance (random), whereas bias is systematic
True or False: "You can reduce bias by increasing sample size." - Answer False, simply
increasing the size of a sample will NOT address bias.
True or False: "You can reduce random error by increasing sample size." - Answer True
List the three main types of bias. - Answer 1. Selection
2. Information
3. Confounding
The following is the research process:
[Target population] ➡ [study sample] ➡ [data collection] ➡ [analysis]
Where in this process can *selection bias* occur?
(a) b/w [Target population] ➡ [study sample]
(b) b/w [study sample] ➡ [data collection]
(c) b/w [data collection] ➡ [analysis]
(d) before [Target population]
(e) after [analysis] - Answer (a) b/w [Target population] ➡ [study sample]
, The following is the research process:
[Target population] ➡ [study sample] ➡ [data collection] ➡ [analysis]
Where in this process can *information bias* occur?
(a) b/w [Target population] ➡ [study sample]
(b) b/w [study sample] ➡ [data collection]
(c) b/w [data collection] ➡ [analysis]
(d) before [Target population]
(e) after [analysis] - Answer (b) b/w [study sample] ➡ [data collection]
The following is the research process:
[Target population] ➡ [study sample] ➡ [data collection] ➡ [analysis]
Where in this process can *confounding* occur?
(a) b/w [Target population] ➡ [study sample]
(b) b/w [study sample] ➡ [data collection]
(c) b/w [data collection] ➡ [analysis]
(d) before [Target population]
(e) after [analysis] - Answer (c) b/w [data collection] ➡ [analysis]
True or False: "A causal pathway can be either direct or indirect." - Answer True
What is the difference between a *direct* causation and an *indirect* causation? - Answer A
*direct causation* indicates that a factor directly causes a disease or health outcome, without
any steps in between, while an *indirect causation* indicates that a factor causes disease, but
not before going through at least one intermediate step.
List the four types of factors when discussing types of causal relationships? - Answer ◾
Necessary and sufficient
◾ Necessary, but not sufficient
◾ Sufficient, but not necessary
◾ Neither necessary, nor sufficient
