Chapter 4

Question 1

population

Answer 1

entire group of individuals we want information from

Question 2

census

Answer 2

collects data from every individual in the population

Question 3

sample

Answer 3

subset of individuals in the population we collect data from

Question 4

sample survey

Answer 4

a study that collects data from a sample to learn about the population from which the sample was selected

Question 5

convince sampling

Answer 5

selects individuals from the population who are easy to reach

Question 6

bias

Answer 6

the design of a statistical study shows bias if it is likely to underestimate or overestimate the value you want to know

Question 7

voluntary response sampling

Answer 7

allows people to choose to be in the sample bu responding to a general invitation

Question 8

random sampling

Answer 8

involves using a chance process to determine which members of a population are included in the sample

Question 9

simple random sampling (SRS)

Answer 9

chosen in a way that every group of n individuals in the population has an equal chance to be selected as the sample

Question 10

sampling with replacement

Answer 10

an individual from a population can be chosen more than once; they are put back into the sample

Question 11

sampling without replacement

Answer 11

an individual from a population can only be chosen once; once they are sampled they are put to the side

Question 12

strata

Answer 12

groups of individuals in a population who share characteristics though to be associated with the variables being measured in a study

Question 13

stratified random sampling

Answer 13

selects a sample by choosing an SRS from each stratum and combining the SRSs into one overall sample
some from all

Question 14

cluster

Answer 14

a group of individuals in the population that are located near each other

Question 15

cluster sampling

Answer 15

selects a sample by randomly choosing clusters and including each member of the selected clusters in the sample
all from some

Question 16

systematic random sampling

Answer 16

selects a sample from an ordered arrangement of the population by randomly selecting one of the first k individuals and choosing every 5th individual after

Question 17

under coverage

Answer 17

occurs when some members of the population are less likely to be chosen or can’t be chosen in a sample

Question 18

nonresponse

Answer 18

occurs when an individual chosen for the sample can’t be contacted or refuses to participate

Question 19

response bias

Answer 19

occurs when there is a systematic pattern of inaccurate answers to a survey question

Question 20

observational study

Answer 20

observes individuals and measures variables of interest but does not attempt to influence the responses
just watching

Question 21

confounding

Answer 21

occurs when two variables are associated in such a way that their effects on a response variable can not be distinguished from each other

Question 22

experiment

Answer 22

deliberately imposes treatments/conditions onto individuals to measure their responses

Question 23

placebo

Answer 23

a treatment that has no active ingredient but is otherwise like the other treatments
the control group

Question 24

treatment

Answer 24

a specific condition applied to the individuals in an experiment

Question 25

experimental unit

Answer 25

an object to which a treatment is randomly assigned

Question 26

subjects

Answer 26

when the experimental units are humans

Question 27

factor

levels

Answer 27

an explanatory variable that is manipulated and may cause a change in the response variable

different values of a factor

Question 28

control group

Answer 28

used to provide a baseline to compare the effects of the other treatments

Question 29

placebo effect

Answer 29

the fact that some subjects in an experiment will respond favorably to any treatment, even if its inactive
gaslighting yourself into thinking its working

Question 30

double blind

single blind

Answer 30

total cluelessness, neither the subjects nor those imposing the treatment know what treatment the subject is receiving; helps eliminate bias

partial cluelessness, either the subject or those imposing the treatment know what treatment the subject is receiving

Question 31

control

Answer 31

keeping other variables constant for all experimental units

Question 32

replication

Answer 32

giving each treatment to enough experimental units so that a difference in the effects of treatments can be distinguished from chance variation due to random assignment

Question 33

completely randomized design

Answer 33

the experimental units are assigned to treatments completely at random

Question 34

block

Answer 34

a group of experimental units that are known before the experiment to be similar in some way that is expected to affect the response to treatments

Question 35

randomized block design

Answer 35

the random assignment of experimental units to treatments is carried out separately within each block

Question 36

matched pairs

Answer 36

compares two treatments that uses block sizes of 2
can be two similar experimental units paired with each other and the treatments are randomly assigned to each person in the pair
each experimental unit can be matched with themselves and the experimental unit would receive both treatments and whatever treatment to start would be randomly selected

Question 37

sampling variability

Answer 37

the fact that different random samples of the same size from the same population produce different estimates

Question 38

statistically significant

Answer 38

observed results of a study are too unusual to be explained by chance
5% threshold: this would be below 5%

Question 39

multistage sampling

Answer 39

two or more sampling methods combined