Sampling Methods & Types of Bias

An auto analyst is conducting a satisfaction survey, sampling from a list of 10,000 new car buyers. The list includes 2,500 Ford buyers, 2,500 GM buyers, 2,500 Honda buyers, and 2,500 Toyota buyers. The analyst selects a sample of 400 car buyers, by randomly sampling 100 buyers of each brand.

What sampling method is described?

• Simple Random Sample (SRS)

• Stratified Random Sample

• Cluster Random Sample

• Systematic Random Sample

• Convenience Sample

A human resources department plans to survey 100 of the 3000 employees in the firm. An alphabetical list of the employees is available, a random number between 1 and 30 is picked and the sample consists of the person that far down the list along with every 30th person after that.

What sampling method is described?

• Simple Random Sample (SRS)

• Stratified Random Sample

• Cluster Random Sample

• Systematic Random Sample

• Convenience Sample

A sales representative wishes to survey her client base of 47 companies. She has 47 business cards, all of the same size, from her contacts in the companies. The sales representative decides to drop them all in a small box, shake them up, and reach in to pick 5 cards for her sample.

What sampling method is described?

• Simple Random Sample (SRS)

• Stratified Random Sample

• Cluster Random Sample

• Systematic Random Sample

• Convenience Sample

A candy manufacturer wants to test consistency of the sugar content of chocolate covered cherries produced in one factory. The company decides to randomly select three boxes of chocolate covered cherries from each day’s production run at the factory and analyze every cherry in each of these boxes as to sugar content.

What sampling method is described?

• Simple Random Sample (SRS)

• Stratified Random Sample

• Cluster Random Sample

• Systematic Random Sample

• Convenience Sample

Investigators chose a SRS of 800 driving adults in NC and questioned them about their driving habits. One question was, “Recalling the last ten traffic lights you drove through, how many of them were red when you entered the intersection?”

What source of bias is shown here?

• Undercoverage

• Response Bias

• Nonresponse Bias

• Voluntary Response Bias

• Convenience Sampling

David hosts a podcast and he is curious how much his listeners like his show. He decides to start with an online poll. He asks his listeners to visit his website and participate in the poll. The poll shows that 91% of the 200 respondents “love” his show.

What source of bias is shown here?

• Undercoverage

• Response Bias

• Nonresponse Bias

• Voluntary Response Bias

• Convenience Sampling

A senator wanted to know about how people in her state felt about internet privacy issues. She conducted a poll by calling 100 people whose names were randomly sampled from the TikTok database of users. The senator’s office called those numbers until the got a response from all 100 people chosen. The poll showed that 28% of respondents were “very concerned” about internet privacy.

What source of bias is shown here?

• Undercoverage

• Response Bias

• Nonresponse Bias

• Voluntary Response Bias

• Convenience Sampling

A survey is sent out to a random sample of adults and asked, “Some cell phone users have developed brain cancer. Should all cell phone come with a warning label explaining the danger of using cell phones?”

What source of bias is shown here?

• Undercoverage

• Wording Bias

• Nonresponse Bias

• Voluntary Response Bias

• Convenience Sampling

On average, how long before class starts do students wake up? Administrators survey a random sample of students that live on campus.

What sources of bias are shown here?

• Undercoverage

• Response Bias

• Nonresponse Bias

• Voluntary Response Bias

Appalachian State wanted to know what percent of its students drink underage. When students met with their advisors to register for classes, they asked every student in person if they consumed alcohol. The data showed that 5% of students participate in underage drinking.

What source of bias is shown here?

• Undercoverage

• Response Bias

• Nonresponse Bias

• Voluntary Response Bias

• Convenience Sampling