ap stats - unit 3 vocab

Question 1

Simple Random Sample (SRS)

Answer 1

1) Label 2) Randomize 3) Select

Question 2

Stratified Random Sample

Answer 2

Split population into groups and choose a SRS from EACH group

Question 3

Systematic Sample

Answer 3

Randomly choosing a start position, then sample with an equal interval between individuals

Question 4

Cluster Sample

Answer 4

Split the population based on LOCATION. Use SRS to choose group(s), then sample ALL individuals in those group(s)

Question 5

Voluntary Response Sample

Answer 5

people who volunteer themselves to respond (due to their own general appeal)

Question 6

Convenience Sample

Answer 6

choosing individuals who are easiest to reach

Question 7

undercoverage

Answer 7

when some groups in the population are left out of the process when choosing the sample

Question 8

nonresponse

Answer 8

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

Question 9

wording of questions

Answer 9

the most influential on answers, if worded wrong, could cause more bias

Question 10

response bias

Answer 10

a systematic pattern of incorrect responses, due to wording of question, LYING, etc…

Question 11

population

Answer 11

a group of individuals that you want information about

Question 12

sample

Answer 12

a subset of the population

Question 13

observational study

Answer 13

observes individuals and measures variable of interest but DOESN’T CHANGE anything to influence responses

Question 14

experiment

Answer 14

imposes some treatment to measure their responses, doing something to CHANGE the results

Question 15

explanatory variable (x)

Answer 15

is used to predict values

Question 16

factors

Answer 16

when there is more than 1 explanatory value

Question 17

levels

Answer 17

when there is more than 1 factor

Question 18

response variable

Answer 18

the outcome(s) recorded

Question 19

treatment

Answer 19

what is being done to the participants

Question 20

experimental units

Answer 20

are the who/what the treatment is imposed on

Question 21

confounding variable

Answer 21

the variable not control, but can affect the results

Question 22

control group

Answer 22

the group with the treatment that has zero level used (like a sugar pill)
provides BASELINE DATA

Question 23

placebo effect

Answer 23

when a “fake” treatment works on a subject (like a sugar pill)

Question 24

single blind

Answer 24

when subjects are unaware of what treatment is being assigned (gets rid of placebo effect)

Question 25

double blind

Answer 25

when BOTH subject and the experimenter don't know what treatment is being assigned (gets rid of placebo effect)

Question 26

4 key principles of experiments (what we can CONCLUDE)

Answer 26

Comparison - need 2 or more treatments Random assignment - use a chance process Control - keep all other variables besides treatments constant Replication - Use enough experimental units to see differences _______ CRCR

Question 27

Completely Randomized design

Answer 27

(similar to SRS) treatments are randomly assigned to a group of experimental units

Question 28

Randomized block design

Answer 28

when experimental units are grouped by some commonality FIRST, then randomly assigned to a treatment

Question 29

matched pair design

Answer 29

VERY SIMILAR experimental units paired up at first, then randomly assign treatments (also can be done with the pair being one person, aka most similar you can get)

Question 30

Causation*

Answer 30

changes in x CAUSES changes in y

Question 31

Confounding*

Answer 31

changes in x causes changes in y BUT y also is caused by confounding variable z

Question 32

Common Response*

Answer 32

changes in BOTH x and y are caused by confounding variables b

Question 33

Statistically significant

Answer 33

a result is unlikely due to chance