The example in the section "Stratified Sampling" assumes that the sample of students was selected using a stratified simple random sampling design. This example shows analysis based on a more complex ...

Suppose that the sample of students described in the previous section was actually selected using stratified random sampling. In stratified sampling, the study population is divided into ...

Previous surveys on enrollments provided information on which to design a stratified-random sample, making use of the principle of optimum allocation. The Journal of the American Statistical ...

For example, one way to further reduce bacteria in formula is using hot water during reconstitution and then cooling it to body temperature prior to feeding.

Learn how simple random sampling works and what advantages it offers over other methods when selecting a research group from a larger population.