Sampling Methods and Design Flashcards

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?

Answer: Cluster sampling

Cluster sampling selects naturally occurring groups (like counties) as the sampling unit rather than individual elements.

In a study, every 8th person on a list is selected after a random start between 1 and 8. What is this method called?

Answer: Systematic sampling

Systematic sampling selects every kth element from a list after a random starting point.

Which of the following best describes non-response bias?

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.

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?

Answer: Disproportional stratified sampling

Disproportional stratified sampling takes equal numbers from strata regardless of their actual size in the population.

What does 'sampling frame' refer to in research design?

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.

A researcher studying rare diseases recruits initial participants and asks them to refer others with the same condition. This method is known as:

Answer: Snowball sampling

Snowball sampling uses existing participants to recruit additional participants, making it useful for hard-to-reach populations.

Which design feature best reduces the chance of a biased sample in a telephone survey?

Answer: Using random digit dialing to reach unlisted numbers

Random digit dialing generates phone numbers randomly, reducing coverage bias by including unlisted numbers.