Chapter 4 Designing Studies Flashcards Preview

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Flashcards in Chapter 4 Designing Studies Deck (25):
1

population

the entire group of individuals about which we want information

2

sample

a part of the population from which we actually collect information, with this information from the sample, conclusions can be drawn about the entire population

3

convenience sample

the result of choosing individuals who are easiest to reach

4

bias

shown in the design of a statistical study if it systematically favors certain outcomes

5

voluntary response sample

consists of people who choose themselves by responding to a general appeal, this shows bias because people with strong opinions are most likely to respond

6

simple random sample (SRS)

consists of n individuals from the population chosen in such a way that every set of n individuals has an equal chance to be the sample actually selected

7

table of random digits

a long string of the digits 0,1,2,3,4,5,6,7,8,9 with the properties; each entry in the table is equally likely to be any of the 10 digits 0 through 9, the entries are independent of each other, knowledge of the table gives no information about any other part

8

stratified random sample

to select one, first classify the population into groups of similar individuals

9

strata

taking a population and classifying it into groups of similar individuals, then choose a separate SRS in each stratum and combine these SRSs to form the full sample

10

cluster sample

to create, first divide the population into smaller groups, then choose an SRS of the clusters, all individuals in the chosen clusters are included in the sample

11

clusters

should mirror the characteristics of the population

12

under coverage

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

13

non response

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

14

observational study

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

15

experiment

deliberately imposes some treatment on individuals to measure their responses

16

confounding

occurs when two variables are associated in such a way that their effects on a response variable cannot distinguish from each other

17

treatment

a specific condition applied to the individuals in an experiment

18

experimental units

the smallest collection of individuals to which treatments are applied

19

subjects

individuals, such as humans where the treatment is applied to

20

random assignment

in an experiment, meaning that experimental units are assigned to treatments at random, using a type of chance process

21

completely randomized design

treatments are assigned to all the experimental units completely by chance

22

double-blind

neither the subjects nor those who are interact with them and measure the response variable know which treatment a subject received

23

statistically significant

an observed effect so large that it would rarely occur by chance

24

block

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

25

randomized block design

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