AP Stats Ch. 4 Vocab

Question 1

Sample

Answer 1

a (representative) subset of a population

Question 2

Population

Answer 2

the entire group of individuals or instances about whom we hope to learn from

Question 3

Sample Survey

Answer 3

a study that asks questions of a sample drawn from some population in hopes of learning something about the whole

Question 4

Voluntary Response

Answer 4

sampling design where individuals can choose to participate (biased because some groups aren’t represented)

Question 5

Confounded

Answer 5

when levels of one factor are associated with the levels of another factor so their effects can’t be separated

Question 6

Design

Answer 6

type of sampling

Question 7

Convenience Sampling

Answer 7

individuals are chosen based of who is easily available

Question 8

Biased

Answer 8

any systematic failure of a sampling method

Question 9

Simple Random Sampling

Answer 9

sampling design in which each set of “x” elements in the population has an equal chance of being selected

Question 10

Table of Random Digits

Answer 10

used for SRS

Question 11

Stratified Random Sampling

Answer 11

sampling design in which the population is divided into several strata and random samples are drawn from each strata

Question 12

Cluster Sampling

Answer 12

sampling design in which entire groups are chosen at random

Question 13

Undercoverage

Answer 13

type of bias that is problematic because some groups aren’t represented in the sample

Question 14

Nonresponse

Answer 14

type of bias that is problematic because the intended sample is incomplete

Question 15

Response Bias

Answer 15

type of bias that is problematic because false info may be given

Question 16

Sampling Frame

Answer 16

a list of individuals from whom the sample is drawn

Question 17

Systematic Random Sample

Answer 17

sample drawn by selecting an individual from a list every nth time

Question 18

Inference

Answer 18

inferring something about a population by examining a sample

Question 19

Strata

Answer 19

name of groups that have been divided from the whole when stratified random sampling is used

Question 20

Parameter

Answer 20

number (quantity) or quality that describes a population

Question 21

Observational Study

Answer 21

Observes individuals and measures but doesn’t influence response

Question 21

Statistic

Answer 21

number (quantity) or quality that describes a sample

Question 22

Experiment

Answer 22

Deliberately imposes some treatment on individuals to measure their response

Question 23

Lurking Variable

Answer 23

Variable that isn’t explanatory or response but influences in some way

Question 24

Experimental Units

Answer 24

Smallest collection of individuals to which treatments are applied

Question 25

Subjects

Answer 25

Human units

Question 26

Treatment

Answer 26

A specific condition applied to the individuals

Question 27

Factors

Answer 27

Combination of values of the explanatory variable

Question 28

Levels

Answer 28

Combing specific values to create a treatment

Question 29

Random Assignment

Answer 29

Experimental units are assigned to the treatments at random

Question 30

Comparative Design

Answer 30

Compares 2 treatments

Question 31

Completely Randomized Design

Answer 31

The treatments are assigned to all the experimental units by chance

Question 32

Control Group

Answer 32

The baseline for comparing g the effects of other treatments

Question 33

Principles of Statistical Design

Answer 33

1. Control: for lurking variables that affect response; use comparative design and assure the difference is only the way treatments are administered 2. Random Assignment: use impersonal chance to assign experimental units to treatments. Crests roughly equivalent groups 3. Replication: use enough units so any differences can be distinguished

Question 34

Placebo Effect

Answer 34

A dummy treatment. Assure the distribution of treatments is the same and subjects don't know which treatment they are receiving.

Question 35

Double-blind

Answer 35

Neither subjects or those who interact and measure the response variable know which treatment a subject receives.

Question 36

Single-blind

Answer 36

Subjects know which treatment they are receiving but individuals who interact with them don't

Question 37

Statistically Significant

Answer 37

An observed effect so large it would rarely occur by chance

Question 38

Block

Answer 38

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 39

Randomized Block Design

Answer 39

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

Question 40

Matched Pair Design

Answer 40

Create blocks by matching pairs if similar experimental units. 1 member gets 1 treatment first and the other member the other treatment