Stats Sample Designs

Voluntary Response Sample (also a bias)

People choose themselves to be in the sample by responding to a general appeal

Convenience Sample (not the name of a bias… instead, it would most likely be undercoverage bias)

Individuals who are easiest to reach are chosen for the sample

Simple Random Sample (SRS)

Individuals are selected so that all the possible combinations of individuals are equally likely to be in the sample

Stratified Random Sample

Divide the population into groups of similiar individuals called strata; choose an SRS in each stratum to form the full sample

Cluster Sample

Involves the division of a population into smaller groups, called clusters. Ideally, there is heterogeneity within each cluster, and clusters are similar to one another in their composition. An SRS is selected from the population to form the sample of clusters. Data are collected from all the observations in the selected clusters.

Multistage Sample

Sampling schemes that combine several methods - NOT ON THE AP EXAM

Systematic Random Sample

The first individual is chosed an random, then a system or rule is used to choose all other individuals