Identifying Bias: Quiz 2

A city in the midwestern United States is considering a plan to add roundabout intersections in some high traffic areas to reduce the number of accidents. One city council member used a phone survey to reach his constituents containing the following question: "Many people object to the city's plan to reduce the unnecessary accidents by turning several intersections into those strange European style roundabouts. Do you also object to it?" He called the homes in his district between during his lunch break at his regular job, which is between 12:00 and 12:30 P.M. Which of the following is a likely source of bias in the survey?

• Calling between 12:00 and 12:30 limits his sample to people who will be at home during those hours, which leaves out everyone who regularly works during that time of day. This might influence the estimate of the proportion of people who object to the plan.

• The phrase "plan to reduce unnecessary accidents" might influence people to voice support for the plan, making the estimate of the proportion of constituents who object to the plan too low.

• The phrases "Many people object" and "Do you also object?" may influence people to say they object, inflating the estimate of the proportion of constituents who object.

• All of these are possible sources of bias for this survey.

Tags

CCSS.RL.11-12.6

A school newspaper is going to investigate students' perceptions regarding the campus security guards. They plan to survey 100 students at the school. The editor-in-chief tells his staff that he is worried about undercoverage bias created by chronically truant students (students who miss an excessive amount of days). His concern is...

• Unwarranted because some students nay refuse to participate and that is inevitable.

• Justified because chronically truant students will be difficult to survey and will probably have a disproportionately negative view of the security guards.

• Unwarranted because students who cannot be surveyed are not a part of the population of interest.

• Unwarranted because students who cannot be surveyed are not a part of the sample.

A local news program decides to conduct a poll to see how its viewers feel about its new programming format. At the end of each program during one week it asks viewers to call in and express their opinions. The station gives one number to dial if you like the new format, and another number to dial if you do not like it. Which of the following is a correct characterization of this sampling approach?

• This sampling approach will be biased because people might dial the number incorrectly, and therefore not everyone will be correctly represented.

• This sampling approach will be biased because the people who call in will be those who have stronger feelings about the new format, and therefore the sample will not be representative of the population.

• This sampling approach will be unbiased because people can call in with either opinion, and therefore the sample will be representative of the population.

• This sampling approach will be unbiased because the station doesn't know who will call in, making it a random sample.

Tags

CCSS.7.SP.A.1

CCSS.HSS.IC.A.1

In a large city school system with 20 elementary schools, the school board is considering the adoption of a new policy that would require elementary students to pass a test in order to be promoted to the next grade. The PTA wants to find out whether parents agree with this plan. They decide to put a big ad in the newspaper asking people to log their opinions on the PTA website.

What is the most concerning source of bias here?

• Voluntary Response Sampling

• Response Bias

• Nonresponse Bias

• Convenience Sampling

Tags

CCSS.HSS.IC.B.3

State police set up a roadblock to estimate the percentage of cars with up-to-date registration, insurance, and safety inspection stickers. They usually find problems with about 10% of the cars they stop.

What is the most concerning source of bias in this situation?

• Voluntary Response Sample

• Response Bias

• Nonresponse Bias

• Convenience Sample

Tags

CCSS.7.SP.A.1

CCSS.HSS.IC.A.1