EXAM 1

Question 1

Data

Answer 1

are collections of observations, such as measurements, genders, or survey responses.

Question 2

Statistics

Answer 2

is the science of planning studies and experiments; obtaining data; and organizing, summarizing, presenting, analyzing, and interpreting those data and then drawing conclusions based on them.

Question 3

Population

Answer 3

Complete collection of all members in a group.

Question 4

Census

Answer 4

Information from a population.

Question 5

Sample

Answer 5

Part of the population.

Question 6

Voluntary Response Sample

Answer 6

A sample where the participants choose if they want to respond.

Question 7

Statistical Significance

Answer 7

The chance of happening randomly is less than 5%.

Question 8

Practical Significance

Answer 8

Does it really matter?

Question 9

Parameter

Answer 9

a numerical measurement describing some characteristic of a [population].

Question 10

Quantitative Data

Answer 10

Consists of numbers representing counts or measurements.

Question 11

Categorical Data

Answer 11

Consists of names or labels (not numbers that represent counts or measurements).

Question 12

Discrete Data

Answer 12

result when the data values are quantitative and the number of values is finite, or “countable”.

Question 13

Continuous Data

Answer 13

result from infinitely many possible quantitative values, where the collection of values is “not countable”.

Question 14

Statistic

Answer 14

is a numerical measurement describing some characteristic of a [sample].

Question 15

Ratio

Answer 15

There is a natural zero starting point and ratios make sense. (Ex. Heights, Volumes, etc.)

Question 16

Interval

Answer 16

Differences are meaningful, but there is no natural zero starting point and ratios are meaningless. (Ex. Body Temp)

Question 17

Ordinal

Answer 17

Data can be arranged in order, but differences either can’t be found or are meaningless. (Ex. Ranks of colleges in U.S)

Question 18

Nominal

Answer 18

Categories only. Data cannot be arranged in order. (Ex. Eye colors)

Question 19

Experiment

Answer 19

we apply some treatment and then proceed to observe its effects on the individuals.

Question 20

Observational Study

Answer 20

we observe and measure specific characteristics, but we don’t attempt to modify the individuals being studied.

Question 21

Replication

Answer 21

is the repetition of an experiment on more than one individual.

Question 22

Blinding

Answer 22

is used when the [subject] doesn’t know whether he or she is receiving a treatment or a placebo.

Question 23

Double-blind

Answer 23

means that blinding occurred at two levels; subject and researcher (doctor)

Question 24

Randomness

Answer 24

is used when individuals are assigned to different groups through a process of random selection

Question 25

Simple Random Sample

Answer 25

A sample of n subjects is selected in such a way that every possible sample of the same size n has the same chance of being chosen.

Question 26

Systematic Sampling

Answer 26

we select some starting point and then select every kth (such as every 50th) element in the population.

Question 27

Stratified Sampling

Answer 27

we subdivide the population into at least two different [subgroups] (or strata) so that subjects within the same subgroup share the same characteristics (such as gender). Then we draw a sample from each subgroup (or stratum).

Question 28

Cluster Sampling

Answer 28

we first [divide] the population area into sections (or clusters). Then we randomly select some of those clusters and choose all the members from those selected clusters.

Question 29

Sampling Error

Answer 29

occurs when the sample has been selected with a random method, but there is a discrepancy between a sample result and the true population result; such an error results from chance sample fluctuations.

Question 30

Confounding

Answer 30

occurs when we can see some effect, but we can’t identify the specific factor that caused it.

Question 30

Nonsampling Error

Answer 30

is the result of human error, including such factors as wrong data entries, computing errors, questions with biased wording, false data provided by respondents, forming biased conclusions, or applying statistical methods that are not appropriate for the circumstances.

Question 31

Nonrandom Sampling Error

Answer 31

is the result of using a sampling method that is not random, such as using a convenience sample or a voluntary response sample.

Question 32

Multistage Sampling

Answer 32

Collect data by using some combination of basic sampling methods.