Sampling Methods, Studies and Bias

Can you differentiate between systematic sampling and cluster sampling?

• Systematic sampling involves selecting a random sample of individuals from each cluster in the population.

• Cluster sampling involves selecting every nth element in a population.

• Systematic sampling involves selecting every nth element in a population, while cluster sampling involves randomly selecting clusters and including all individuals within those clusters in the sample.

• Cluster sampling involves randomly selecting clusters and including all individuals within those clusters in the sample, while systematic sampling involves selecting every nth element in a population.

Identify the type of sampling used:

Interview every 10th student who enters the school in the morning.

• simple random sample

• voluntary response sample

• systematic sample

• convenience sample

Identify the type of sampling used:

Assign each car in a dealership a number and then use a random-number table to select the cars to be inspected.

• systematic sample

• simple random sample

• convenience sample

• voluntary response sample

Identify the type of sampling used:

Marianne wanted to know students' opinion on the new schedule at school. She survey's the first 30 students who come into her class.

• Convenience Sampling

• Systematic Random Sampling

• Simple Random Sampling

• Volunteer response

An independent research company wants to go door to door to survey people in the city of West Palm Beach. The company decides to number all blocks within the city limits, randomly choose 1 block, and then survey all households on that block.

This is an example of:

• Simple Random Sample

• Stratified Random Sample

• Cluster Random Sample

• Systematic Random Sampling

Identify the type of sampling used:

A teacher splits her classes up by period. She then uses a RNG to select 10 students from each period to participate in a survey.

• Stratified Random Sample

• Systematic Random Sample

• Cluster Random Sample

• Biased Sample

Why do we randomly select our samples?

• for control

• reduce bias

• so we don't get the same answers from everyone

• to eliminate confounding results

I want to estimate the proportion of people in North Palm Beach who own cats. I stand outside a NPB pet store and ask every 4th person whether they own a cat or not. What is the most prominent kind of bias evident?

• Undercoverage

• Response

• Non-Response

• Voluntary Response

16 out of the 20 people who called into a radio station said that they enjoy the station's morning programming. What type of bias is demonstrated here?

• Voluntary Response Bias

• Nonresponse Bias

• Undercoverage Bias

An employer wants to know how their 500 employees like working for them. Which is the most representative sample?

• Ask the first 75 people to show up for work

• Randomly select the names of 10 employees

• Poll the Employees of the Month for the past year

• Randomly select the names of 75 employees