A simple random sample is used to represent the entire data population. A stratified random sample divides the population into smaller groups based on shared characteristics.

What is the difference between representative samples and random samples, and how are they are used to reduce sampling bias?

Visualizing a simple random sample: Simple Random Sample of Lotto Balls This applet animates the random sampling of lotto balls. The population size can be set anywhere between 1 and 144. Users can ...

The stratified random sample is always at least as accurate on the average as the random sample and its relative efficiency is a monotone increasing function of the size of the sample. No general ...