FAST Sampling Methods and Design 2 — Questions and Answers
Question 1: A researcher wants to study voting intentions across 10 states and randomly selects entire counties rather than individual voters. This is an example of which sampling method?
- Systematic sampling
- Cluster sampling (Correct answer)
- Stratified sampling
- Convenience sampling
Correct answer: Cluster sampling
Cluster sampling selects naturally occurring groups (like counties) as the sampling unit rather than individual elements.
Question 2: In a study, every 8th person on a list is selected after a random start between 1 and 8. What is this method called?
- Simple random sampling
- Cluster sampling
- Systematic sampling (Correct answer)
- Quota sampling
Correct answer: Systematic sampling
Systematic sampling selects every kth element from a list after a random starting point.
Question 3: Which of the following best describes non-response bias?
- Selecting participants using a biased random number generator
- When those who respond differ systematically from those who do not (Correct answer)
- Using a sample that is too small for the population
- Choosing participants from only one geographic region
Correct answer: When those who respond differ systematically from those who do not
Non-response bias occurs when people who decline to participate differ in meaningful ways from those who do respond.
Question 4: A population has four age groups: 18-25, 26-40, 41-55, and 56+. A researcher samples 50 people from each group. What type of sampling is this?
- Proportional stratified sampling
- Disproportional stratified sampling (Correct answer)
- Simple random sampling
- Multistage sampling
Correct answer: Disproportional stratified sampling
Disproportional stratified sampling takes equal numbers from strata regardless of their actual size in the population.
Question 5: What does 'sampling frame' refer to in research design?
- The margin of error in the sample
- The list or source from which sample members are drawn (Correct answer)
- The timeframe during which data is collected
- The statistical formula used to analyze results
Correct answer: The list or source from which sample members are drawn
A sampling frame is the actual list or source used to identify and select sample members from the target population.
Question 6: A researcher studying rare diseases recruits initial participants and asks them to refer others with the same condition. This method is known as:
- Convenience sampling
- Snowball sampling (Correct answer)
- Purposive sampling
- Quota sampling
Correct answer: Snowball sampling
Snowball sampling uses existing participants to recruit additional participants, making it useful for hard-to-reach populations.
Question 7: Which design feature best reduces the chance of a biased sample in a telephone survey?
- Calling only landlines to ensure older participants
- Using random digit dialing to reach unlisted numbers (Correct answer)
- Interviewing callers during business hours only
- Limiting calls to one geographic region
Correct answer: Using random digit dialing to reach unlisted numbers
Random digit dialing generates phone numbers randomly, reducing coverage bias by including unlisted numbers.
FAST Sampling Methods and Design 2
A researcher wants to study voting intentions across 10 states and randomly selects entire counties rather than individual voters.
This is an example of which sampling method?