Stats Test 1

Question 1

What is Statistics?

Answer 1

1. science of extracting meaning from data
2. art of persuading the universe to divulge information about
   itself
3. methodology for using data to answer questions in the
   presence of variation

Question 2

Dogma of Statistics

Answer 2

Variation -> Uncertainty -> Dealing with and understanding uncertainty to extrapolate meaning

Question 3

Process of Statistical Problem Solving

Answer 3

Collect -> Summarize -> Interpret (data)

Question 4

Population

Answer 4

Entire group of individuals

Question 5

Sample

Answer 5

Subgroup of the Population

Question 6

Population fact

Answer 6

Parameter

Question 7

Sample fact

Answer 7

statistic

Question 8

Convenience sampling

Answer 8

Select people in the most convienient way

Question 9

Volunteer Response Sampling

Answer 9

Individuals select themselves

Question 10

Quota Sampling

Answer 10

Force the sample to meet specified quotas

Question 11

Probability Sampling Designs

Answer 11

simple random sampling
cluster sampling
stratified random sampling
multistage sampling

Question 12

Cluster Sampling

Answer 12

blocks are similar to population

random sample of clusters is taken

all individuals in the selected clusters are included in the
sample

Question 13

Stratified Random Sample

Answer 13

classify population into groups (strata) that are different
from each other

individuals within a group (stratum) share a similar characteristic

select SRS from every group

combine SRS’s

Question 14

Multistage Sample

Answer 14

(Lightning)
SRS of states

for selected states, SRS’s of counties

for selected counties, SRS’s of people

combine SRS’s of people

Question 15

Continuous Quantitative variable

Answer 15

Any number

Question 16

Discrete Quantitative variable

Answer 16

Only whole numbers

Question 17

Discrete Categorical variable

Answer 17

Only categories

Question 18

Observational Studies

Answer 18

individuals choose which treatment to receive or naturally
belong to one of the treatment groups

lurking variables that influence choice confounded with
treatments

passive data collection: observing, measuring, counting,
subjects are undisturbed

media often improperly attribute cause-effect conclusions
to these

Question 19

Experiment

Answer 19

a study design where treatments are imposed on subjects before observing response (manipulations, interventions)

Question 20

Response variable

Answer 20

characteristic measured on each subject; outcome of interest

Question 21

Explanatory variable

Answer 21

used to predict or explain changes in the response variable

Question 22

Factor

Answer 22

planned explanatory variable (umbrella term for all treatments)

Question 23

Treatment

Answer 23

the condition or conditions applied to a subject or individual in an experiment

Question 24

Principles of Valid Experiments

Answer 24

1. Control/Comparison
2. Randomization
3. Replication
4. (Double-Blinding)

Question 25

Hawthorne Effect

Answer 25

phenomenon where people in an
experiment behave differently from how they would
normally behave; attention/observation bias

Question 26

Randomized Controlled Experiment (RCE)

Answer 26

Subjects assigned to treatments such that each subject has an
equal chance of being assigned to any possible treatment
(typically with the same number of subjects per treatment)

Question 27

Randomized Block Design (RBD)

Answer 27

An experimental design where the random assignment of
individuals to treatments is carried out separately within
each block.

Question 28

Matched Pairs

Answer 28

Special case of randomized block designs
Twins: each receiving a treatment
Two treatments on each individual
Measurements before and after treatment on each
individual

Question 29

What can you extrapolate from a well-designed experiment that you cannot extrapolate from a study?

Answer 29

A cause and effect relationship

Question 30

What is a distribution of a random variable?

Answer 30

A list of possible values of a variable together with how often each value occurs

Question 31

Why do we randomize in experiments

Answer 31

To eliminate bias associated with lurking variables

Question 32

Why do we use replication in experiments?

Answer 32

To remove extraneous variation from the experiment error

Question 33

Probability samples are samples selected in such a at that

Answer 33

all samples of size n have the same chance of being selected

Question 34

Jane, a student at BYU, decides to study opinions of BYU students concerning grading in religion classes. She obtains a roll from every religion class and randomly selects five students on each roll. This is an example of

Answer 34

Stratified sampling

Question 35

The explanatory variable is

Answer 35

factor status

Question 36

Empirical rule

Answer 36

68 95 99.7
1sd 2sd 3sd