Module 0

Question 1

Population Inference: We should only make population inferences when we have…

Answer 1

Random Sampling

Question 2

Population Inference: What is Randomization?

Answer 2

It’s the elimination of the effects of unknown extraneous factors (factors not being studied/observed).

Question 3

Population Inference: What is a Population Inference?

Answer 3

Drawing a conclusion based on the assumption that the observed data set reflects the given population’s condition.

Question 4

Population Inference: Non-random sampling leads to…

Answer 4

Biased results

Question 5

Random Sampling Methods: Describe Simple Random Sampling?

Answer 5

Each sample of size n in the population has the same chance of being selected.

Question 6

Random Sampling Methods: Describe Stratified Random Sampling?

Answer 6

Population is divided into different homogeneous (identical) groups called strata. SRS is then done within every stratum.

Question 7

Random Sampling Methods: Describe Systematic Random Sampling?

Answer 7

Start from a randomly selected individual, then sample every n person.

Question 8

Random Sampling Methods: Cluster Random Sampling

Answer 8

Splitting the population into similar groups, then selecting one or a few clusters at random. A census (complete count) is then performed.

Question 9

Sources of Bias: Describe Selection Bias?

Answer 9

A portion of the population is not sampled at all or has a smaller representation in the sample than in the population.

Question 10

Sources of Bias: Describe Response Bias?

Answer 10

Anything in the survey design that influences the responses.

Question 11

Sources of Bias: Describe Voluntary Response Bias?

Answer 11

Occurs when individuals can choose on their own whether to participate in the sample.

Question 12

Sources of Bias: Describe Nonresponse Bias?

Answer 12

Occurs when a large proportion of those sampled fail to respond.

Question 13

Casual Inference: Casual inferences should only be made when we have…

Answer 13

Random Allocation

Question 14

Casual Inference: Describe Random Allocation?

Answer 14

A method of choosing individuals for treatment and control groups entirely by chance with no regard for the will of researchers, patients, conditions, or preferences.

Question 15

Study Designs: Describe Observation Studies?

Answer 15

Investigator observes individuals, measures variables of interest, determines trends and possible relationships, and finally does not determine causal relationship.

Question 16

Name the types of Observational Studies and describe each of them.

Answer 16

Retrospective - Individuals are sampled and information is collected about their past.
Prospective Study - Individuals are followed over time and data about them is collected as their characteristics change.

Question 17

Study Design: Describe Randomized Experiment?

Answer 17

An experiment is a study design that allows us to prove a cause and effect relationship.