The aims of this study were, first to describe the dental history and oral hygiene practices in a cluster random sample of 14-year-old children in Birmingham UK. Secondly, to determine whether the ...

The random sample survey is a commonly used method in market research and such surveys generally are considered to provide more robust results than purposive or convenience (such as quota) samples.

Consider the example in the section "Stratified Sampling". The study population is a junior high school with a total of 4,000 students in grades 7, 8, and 9. Researchers want to know how much these ...