AP Stats 4.1

population

entire group of individuals

sample

a subset of the population. should be representative of the population

sampling frame

a list of the individuals who compromise the population

census

a sample that includes the entire population

sampling variability

the natural variation that is inherent in sampling

Parameter

A numerical value of some characteristic of a population

statistic

a known numerical value calculated from a sample

simple random sampling

an SRS of size n in a design in which each individual has an equal chance of being selected and each group has an equal chance of being selected

stratified random sampling

A sampling design that first subjectively divides the population into homogeneous groups. An SRS is then taken from each of these groups

cluster sampling

divide the population into heterogeneous groups, and then an SRS is chosen of the sum of the clusters

Systematic sampling

selecting every nth individual from a population. Every individual has the same chance of being chosen, however, each group does not have an equal chance.

multi stage random sample

a sampling design which combines several of the above methods

bias

Systematically favoring certain outcomes

undercoverage

a sampling design that leaves out a segment of the population

voluntary response

When the sample participants are self selected

convenience a sample

A sampling design that uses individuals from the population that are conveniently available

non-response bias

occurs when the individuals selected cannot be contacted declined to participate or do not answer

response bias

Any part of a survey that influences a response