Studied by 197 people

5.0(3)

Get a hint

Hint

1

Sample Survey

An inquiry that asks questions of individuals drawn from a population (such as a poll)

New cards

2

Census

A sample that consists of the entire population

New cards

3

Population

The entire group about whom a statistician hopes to learn

New cards

4

Sample

A portion of a population examined to learn about that population

New cards

5

Population Parameter

A numerical attribute for an entire population (rarely know this)

New cards

6

Sample Statistic

A numerical attribute calculated for sampled data and used to *infer* the associated population parameter

New cards

7

Sample Size

The number of individuals, n, in a sample

New cards

8

Randomization

Each individual is given a fair, random chance of selection

New cards

9

Representative

The sample statistic(s) computed from a sample accurately reflect(s) the corresponding population parameter(s)... you took a "good sample"

New cards

10

Simple Random Sampling (SRS)

Each combination of n individuals in a population has an equal chance of selection... often done by assigning a number to each individual and generating n random numbers

New cards

11

Stratified Random Sampling

Sampling method where the population is divided into several homogeneous subsets (called strata) and THEN random samples are proportionally drawn from each stratum

New cards

12

Cluster Sampling

Sampling method where entire groups or "clusters" or subjects are selected at random; the clusters must be heterogeneous and individually representative of the population

New cards

13

Systematic Sampling

Sampling method in which subjects are listed as one subject is selected, followed by each of the next nth subjects

New cards

14

Sampling Variability

The natural tendency of randomly drawn samples to differ from one another

New cards

15

Sampling Bias

Systematic failure of a sampling method to properly represent its population

New cards

16

Voluntary Response Bias

Individuals must volunteer or take some prior action to be included in a sample

New cards

17

Convenience Sampling Bias

Subjects chosen for a sample are simply those conveniently available due to some factor

New cards

18

Undercoverage Bias

Some portion of the population is not sampled at all or has a reduced chance of being included in the sample

New cards

19

Nonresponse Bias

A substantial fraction of those properly sampled fail to respond

New cards

20

Response Bias

Anything in a survey design that influences the responses, such as wording survey questions in a way that suggests a favored response or perceived pressure in the survey

New cards

21

Observational Study

Study in which the researchers do not assign treatments, they simply observe them

New cards

22

Retrospective Study

Observational study in which subjects are selected and then their previous conditions or behaviors are observed

New cards

23

Prospective Study

Observational study in which subjects are selected and then followed to observe future outcomes

New cards

24

Experiment

An experimenter controls factor levels to create treatments, randomly assigns subjects to those treatments, replicates the experiment with all of those subjects, and then compares the responses of the subjects

New cards

25

Completely Randomized Design

Every subject and combination of subjects has an equal chance of receiving each treatment

New cards

26

Factor

An explanatory variable whose levels are controlled by an experimenter

New cards

27

Response Variable

The variable whose resulting values are compared across different treatments

New cards

28

Level

The specific value that the experimenter chooses for a factor

New cards

29

Treatment

The controlled circumstances applied to experimental groups, made of different levels of a single factor or combinations of two or more factor levels

New cards

30

Control Group

A baseline treatment level that provides a basis for comparison; often either a well-understood level or a null treatment

New cards

31

Subject/Experimental Unit

Individuals or objects on whom an experiment is performed

New cards

32

Randomization

An experiment must assign subjects to treatment groups at random

New cards

33

Replication

Each treatment must be repeated for multiple subjects

New cards

34

Statistically Significant

When an observed difference is too large to believe that is was likely to have occurred naturally

New cards

35

Single-Blind

When either the subjects themselves or the administrators/evaluators in an experiment are unaware of which subjects were assigned to each treatment group

New cards

36

Double-Blind

When both subjects themselves and the administrators/evaluators in an experiment are unaware of which subjects were assigned to each treatment group

New cards

37

Placebo

A treatment known to have no effect, administered to the control group so that all groups experience the same condition (such as a sugar pill)

New cards

38

Placebo Effect

A perceived reaction to an ineffective treatment... mist compare to a placebo to be sure that the observed effect of a treatment is not simply due to the placebo effect

New cards

39

Blocking

Grouping subjects together by uncontrollable attributes, thus allowing an experimenter to isolate the variability attributable to differences in the blocks and see the differences caused by the treatments more clearly

New cards

40

Randomized Block Design

Experimental design in which randomization occurs only within blocks; treatment groups are not mixed for different blocks

New cards

41

Confounding Variable

When the levels of one factor are associated with the levels of another factor and this their effects cannot be separated

New cards

42

Matched Pairs Design

Experimental design where the same individual for multiple treatment trials or individuals with similarities not under study are paired together when undergoing the experiment, hopefully reducing the variation in the data from other factors

New cards