3. Sampling

Question 1

What are the two directions or “sign” of a relationship

Answer 1

1. Positive: When X goes up, Y goes up
2. Negative: When X goes up, Y goes down

Question 2

What are two types of Research Studies

Answer 2

1. Observational Studies (collecting data while not directly impacting how the data arise)
2. Experiments (researchers manipulate a variable and look for an effect: must have control group and experimental group)

Question 3

Why are experiments great at finding causal relationships?

Answer 3

Experiments address spuriousness by having a control group and an experimental group - and these groups are split randomly.

Question 4

Randomization kills any possible…

Answer 4

…spurious variable’s cause of X. Randomization ensures that any potential confounding variables (Z) are evenly distributed across the groups.

Question 5

Sampling frame

Answer 5

the set of cases that could be selected into the sample

Question 6

You draw from the population to get a sample and the sample is for

Answer 6

generalization to the public

Question 7

how much your sample is like the population

Answer 7

Representativeness

Question 8

the idea that your sample will tell us something about a larger group than just the sample

Answer 8

Generalizability

Question 9

What are the two types of sampling?

Answer 9

1. Probability Sampling (the chance of a unit’s selection is known, and has a non-zero chance)
2. Non-Probability Sampling (the chance of a unit’s selection is unknown - not everyone has a chance to get selected)

Question 10

What’s an example of a non-probability sample?

Answer 10

Convenience Sample

Question 11

4 Types of Probability Sampling

Answer 11

1. Simple Random Sample (truly random)
2. Systematic Sample (every nth)
3. Cluster Sample
4. Stratified Sample

Question 12

What probability sampling randomly samples existing clusters first then samples within those groups?

Answer 12

Cluster Sample

Question 13

What probability sampling creates subgroups of the sample based on variables then samples from within those subgroups?

Answer 13

Stratified Sample