Chapter 4

Question 1

Population

Answer 1

The entire group of people you want information about in a statistical study

Question 2

Census

Answer 2

Sampling every individual in the population

Question 3

Sample

Answer 3

Ways to chose a sample from a population

Question 4

Convenience sample

Answer 4

Choosing individuals from the population who are easy to reach results in

Question 5

Bias

Answer 5

Consistently overestimate or consistently underestimate the value you want to know

Question 6

Voluntary response sample

Answer 6

Consist of people who choose themselves by responding to a general invitation

Question 7

Random sampling

Answer 7

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

Question 8

Simple random sample (SRS)

Answer 8

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

Question 9

Sampling badly

Answer 9

Using sampling bias

Question 10

Stratified random sample

Answer 10

Starts by classifying the population of similar individuals, called strata. Choose a separate SRS in each stratum and combine them to form the sample

Question 11

Strata

Answer 11

Classifying the population into groups of similar individuals

Question 12

Cluster sample

Answer 12

Start by classifying the population into groups of individuals that are located near each other, called clusters. Choose an SRS of the clusters. All individuals in cluster are in sample

Question 13

Cluster

Answer 13

Classifying the population into groups of individuals that are located near each other

Question 14

Inference

Answer 14

The proves of drawing conclusions about a population on the bias of sample data

Question 15

Undercoverage

Answer 15

Occurs when some members of the population cannot be chosen in the sample

Question 16

Nonresponse

Answer 16

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

Question 17

Observational study

Answer 17

Observes individuals and measures variables of interest but does not attempt to influence the responses

Question 18

Experiment

Answer 18

Deliberately imposes some treatment on individuals to measure their respinses

Question 19

Confounding

Answer 19

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

Question 20

Treatment

Answer 20

A specific condition applied to individuals in an experiment

Question 21

Experimental units

Answer 21

The smallest collection of individuals to which treatments are applied

Question 22

Subjects

Answer 22

Human beings that are experimental units

Question 23

Factors

Answer 23

Explanatory variables in an experiment

Question 24

Random assignment

Answer 24

Experimental units are assumed to treatments using a chance process

Question 25

Completely randomized design

Answer 25

The experimental units are assigned to the treatments completely by chance

Question 26

Control groups

Answer 26

Provides a baseline for comparing the effects of other treatments

Question 27

Control

Answer 27

Keep other variables that might effect the response the same for all groups

Question 28

Replication

Answer 28

Using enough experimental units to distinguish a difference in the effects of treatments from chance variation due to random assignment

Question 29

Blind

Answer 29

Experiment in which the subjects are unaware of which treatment they are receiving

Question 30

Double blind

Answer 30

Experiment in which neither the subjects or the people who interact with them and measure their response variable know which treatment a subject has

Question 31

Statistically significant

Answer 31

An observed effect so large that it would rarely occur by chanve

Question 32

Block

Answer 32

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 the treatments

Question 33

Randomized block design

Answer 33

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

Question 34

Matched pairs

Answer 34

A type of randomized block design for comparing two treatments in which the idea is to create blocks by matching pairs of similar experimental units

Question 35

Causation

Answer 35

When changes in the explanatory variable cause changes in the response variable

Question 36

3 pillars of an experiment

Answer 36

1. Random 2. Replication 3. Control

Question 37

What does replication do?

Answer 37

Reduces variability

Question 38

What does control do?

Answer 38

Controls/eliminates lurking or confounding variables

Question 39

Completely randomized experiment

Answer 39

SRS of experiments

Question 40

Block design

Answer 40

Stratified experiment

Question 41

Random sampling

Answer 41

HOW you choose people to be a part of a study

Question 42

Random assignment

Answer 42

Occurs AFTER people are selected

Question 43

Placebo effect

Answer 43

When a fake treatment works

Question 44

What are the benefits of an experiment?

Answer 44

If all 3 pillars are met, then causation can be made

Question 45

What do experiments do?

Answer 45

IMPOSE A TREATMENT

Question 46

Simple random sample (SRS)

Answer 46

Number the population, choose the sample by random *use in experiments, helps divide groups evenly

Question 47

Stratified

Answer 47

Split population into similar groups. Then sample from each group

Question 48

Cluster

Answer 48

Split population into groups. Sample. Then choose ENTIRE groups of people

Question 49

Systematic

Answer 49

Number the population, randomly choose a PLACE then choose every _th person

Question 50

Multistage

Answer 50

Divide groups into equal areas and randomly choose areas (geographic)

Question 51

Convenience (ex of bias)

Answer 51

Individuals easiest to reach

Question 52

Voluntary (ex of bias)

Answer 52

People volunteer to participate by responding

Question 53

Nonresponse

Answer 53

Majority of population didn’t answer