Bias in Surveys

Choosing the Best Sample Group

100

Marsha wants to find out how other students at her school get to school each day. Which of the following groups, if surveyed, would give her the most accurate sample of the student body? a.her homeroom class b.the students on her bus c.students waiting in the carpool area d.members of the cycling club

A- her homeroom class.

200

Wendy wants to take a survey to determine which flavor of ice cream is the most popular at her school. Which of the following methods is the best way for her to choose a random sample of the students at her school? a.selecting ten students from each homeroom b.selecting members of the boys’ basketball team c.selecting members of the girls’ softball team d.selecting students who like her favorite flavor of ice cream

A- selecting 10 students from each homeroom

300

Jeanette wants to determine the most popular car in town. Which plan would give Jeanette the most accurate results? a.Conduct a sample survey of the cars in her schools’ parking lot at 1:30 on a school day. b.Conduct a random telephone survey of people who live in her state. c.Conduct a sample survey of the cars that are advertised in the local newspaper. d.Conduct a random survey of people entering a large grocery store in her town.

D- Conduct a random survey of people entering a large grocery store in her town.

400

4.Nick wants to determine the amount of time seventh-grade students spend studying for their math exam. Which sampling method would be most unbiased? a.Survey the 15 girls in his class. b.Survey 60 seventh-grade students. c.Survey his 3 best friends. d.Survey the 13 boys in his class.

B - Survey 60 7th-grade students

500

Celia has a large container in which four different kinds of coins are thoroughly mixed. She wants to take a sample of her coins to estimate which kind of coin she has the most. Which of the following methods is the best way for her to select a sample? a.taking one coin from the container b.taking coins until she has one of every kind c.taking ten coins of each type from the container d.taking thirty coins out of the container without looking

D- Taking 30 coins out of the container without looking

Biased/Unbiased Questions

100

Biased or Unbiased and Why? Are you willing to deal with noisy, heavy increases in traffic where you live just so another unnecessary mall can be built?

Biased- noisy, heavy traffic increases and unnecessary mall

200

Biased or Unbiased and Why? Do you support the governor's proposal to reduce state taxes?

Unbiased- This is just asking an opinion without trying to influence the decision.

300

Biased or Unbiased and Why? Do you think soft, furry cats are better than big, bad, barking dogs?

Biased- adjectives make the cats sound better.

400

Biased or Unbiased and Why? Are you willing to pay higher taxes so that the city can build a new stadium?

Unbiased- There are no adjectives about the stadium to influence you.

500

Biased or Unbiased and Why? Would you prefer to take a long, difficult essay test or a quick, simple multiple choice test?

Biased- The adjectives describing each test make the essay sound worse than the multiple choice.

Choosing the Best Sample Group

100

A pizzeria wants to know what topping they should add to their menu. Which sample would give the best result: A) Survey every person at a local ice-cream shop. B) Survey the first 10 people that come to the pizzeria. C)Survey the employees at the pizzeria. D) Survey every person that eats at the pizzeria on Tuesday.

D- More people in the population will get surveyed since everyone can answer.

200

The principal wants to know how many hours of homework students at Northwood get. Which group of people should she ask to get a representative sample? A) Northwood teachers B) Northwood students' parents C) Every 5th student to enter the cafeteria D) Band students

C- This sample would have people from every grade level in it.

300

The 7th grade teachers want to know which activities to add to field day. Which group should they ask? A) The track team. B) Mrs. Lenharth's homeroom. C) 2 students from each 7th grade homeroom. D) Every 3rd 7th grader in the hall during class transisition.

D) This sample would have the most people in the population.

400

A store in the mall wants to know the most popular phone with teenagers. Which group should they ask? A) Teens in the Apple Store B) Parents C) Every 10th person who enters the mall D) Teens in the Verizon store

D- This is the only sample that represents the whole population.

500

A company wants to know how much sleep middle schoolers get at night. Which sample is the least biased? A) Ask all the 8th graders in Tennessee. B) Ask all the 6th graders in Texas. C) Ask all the 6th, 7th, and 8th graders in Iowa. D) Ask a random sample of 6th, 7th, and 8th graders in every state.

D- This sample has representatives from every state and grade level.

Biased or Unbiased?

100

Biased or Unbiased and Why? You survey customers at a mall. You want to know which stores they shop at the most. You walk around a computer shop and choose 20 customers there for your survey.

Biased- Computer store shoppers will say the computer store.

200

Biased or Unbiased and Why? A country radio station wants to know what the most popular type of music is, so they ask their listeners to call in to say their favorite type.

Biased- Only asking people who listen to country music leaves out other music lovers.

300

Biased or Unbiased and Why? I don’t like these shoes, do you?

Biased- Influences people by saying "I don't like."

400

Biased or Unbiased and Why? Do you watch TV on Saturday like everybody else?

Biased- "like everybody else"

500

Biased or Unbiased and Why? You want to know what 7th graders think of their math class. You poll 100 random 7th graders.

Unbiased- 100 people is a large group and they were randomly selected.