# 20_Sampling_Methods_.pdf - Name Types of Sampling Date AP...

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Name ______________________________ Date __________ Types of Sampling AP Statistics Do now: The following diagrams represent different sampling techniques. Look at each diagram and try to determine what is being conveyed. Every combination of 6 individuals simple Random sample srs has the same probability of being selected stratification Homogeneous grouping Then randomly selected cluster Heterogeneous grouping Then randomly selected 3 groups and sampled every one in these groups Heterogeneous grouping Multistage Randomly selected 3 groups are randomly selected within those groups systematic chooseevery nth
Vocabulary Toolkit: Common Types of Sampling Methods: Convenience Sampling (see previous vocabulary toolkit for definition; not a very good sampling method because it often results in bias) Simple Random Sample (SRS ) : In an SRS, every combination of n people are equally likely to be selected. o Ex. Put all of the names of players in the NBA in a database. Use a random number generator to pick 12 players. Cluster Sample: When a population is divided into heterogeneous groups or clusters, and then one entire cluster is sampled. o Ex. Randomly pick three 9 th grade advisories and survey every student in the advisories chosen. Systematic Sample: A random starting place is selected, and then every nth place/subject after that is sampled. o Ex. Randomly pick one name in the phone book. Then call every 100 th person. Stratification: Divide the population into homogeneous subgroups (“strata”). Then randomly select a certain number of objects/subjects from each subgroup. o Ex. Obtain a list of registered voters in a town. Survey 10 people who are registered Democrats, 10 people who are registered Republicans, and 5 people who are registered as independents.