Chapter 4 (Unit 1)

Question 1

The entire group of individuals about which we want information in a statistical study.

Answer 1

population

Question 2

The part of the population from which we actually collect information. We use information from this to draw conclusions about the entire population.

Answer 2

sample

Question 3

When a sample is selected from the population of all individuals about which we desire information (and base conclusions).

Answer 3

sample survey

Question 4

When we choose individuals for a sample who are easiest to reach results.

Answer 4

convenience sample

Question 5

The design of a statistical study that systematically favors certain outcomes; using a method that will consistently overestimate or underestimate the unknown value.

Answer 5

bias

Question 6

A sample that consists of people who choose themselves by responding to a general appeal. This type of sample shows bias because people with strong opinions (often in the same direction) are most likely to respond.

Answer 6

voluntary response sample

Question 7

A subset of a statistical population in which each member of the subset has an equal probability of being chosen. This type of sample is meant to be an unbiased representation of a group.

Answer 7

simple random sample (SRS)

Question 8

A long string of the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. Each entry in this is equally likely to be any of the 10 digits 0-9. The entries are independent of each other. That is, knowledge of one part of the table gives no information about any other part.

Answer 8

table of random digits

Question 9

To select this type of sample, first classify the population into groups of similar indiviudals, called strata. Then choose a separate SRS in each stratum and combine these SRS’s to form the full sample.

Answer 9

stratified random sample

Question 10

Important groups

Answer 10

strata

Question 11

In this type of sample, the bottom population is divided into smaller groups. These groups mirror the characteristics of the population. Then you choose an SRS of these smaller groups. All individuals in the chosen smaller groups are included in the sample.

Answer 11

cluster sample

Question 12

The process of drawing conclusions about a population on the basis of sample data.

Answer 12

inference

Question 13

When errors occur during the act of choosing a sample.

Answer 13

sampling errors

Question 14

This occurs when some groups in the population are left out of the process of choosing the sample. They are represented inadequatley in the sample.

Answer 14

undercoverage

Question 15

Errors that can plague even a census (errors arising during the course of all survey activities other than sampling).

Answer 15

nonsampling errors

Question 16

This occurs when an individual chosen for the sample can’t be contacted or refuses to participate. (nonsampling error)

Answer 16

nonresponse

Question 17

A systematic pattern of incorrect responses in a sample survey leads to this.

Answer 17

response bias

Question 18

The most important influence on the answers given in a sample survey.

Answer 18

wording of questions

Question 19

What is the problem with convenience samples?

Answer 19

They can create bias within the project.

Question 20

Why don’t we always us a simple random sample (SRS)?

Answer 20

Because they are not realistic for a large population size, and can be dificult to manage.

Question 21

What is a margin of error?

Answer 21

Margin of error tells us how much sampling variability to expect, which can be controlled by choosing the size of our random sample.

The smaller the sample, the larger the margin of error.

Question 22

What is response bias?

Answer 22

When a participant gives incorrect responses.

• race
• gender
• interviewer
• recalling past events/inaccurate memory

may all cause.

Question 23

If you placed an announcement in the newspaper asking people to call their council representative to register their opinions, it would be this type of sampling method?

Answer 23

voluntary response

Question 24

If you have a council member survey 50 friends, neighbors, or co-workers, it would be this type of sampling method?

Answer 24

judgement

Question 25

If you have the Board of Elections assign each voter a number, then select 400 of them using a random number table, it would be this type of sampling method?

Answer 25

simple random sample (SRS)

Question 26

If you went to a downtown street corner, a grocery store, and a shopping mall, and interviewed 100 typical shoppers at each location, it would be this type of sampling method?

Answer 26

convenience

Question 27

If you randomly picked 50 voters from each election district, it would be this type of sampling method?

Answer 27

stratified

Question 28

If you called every 500th person in the phone book for a survey, it would be this type of sampling method?

Answer 28

systematic

Question 29

If you randomly picked several city blocks, then randomly picked 10 residents from each block, it would be this type of sampling method?

Answer 29

multistage

Question 30

If you randomly selected several city blocks, and interviewed all of the adults living on each block, it would be this type of sampling method?

Answer 30

cluster