Stratified sampling is used to select a sample that is representative of different groups. If the groups are of different sizes, the number of items selected from each group will be proportional to ...

Techniques for using electoral registers to provide a sampling frame for the general population are already well established. The best known is that used on the National Readership Survey and most ...

When sampling a population, the numbers of organisms are counted within a sample site, and then the results multiplied to estimate the total number in the entire habitat. Large animals and plants can ...

In a simple random sample, each individual in the population has an equal probability of being chosen. Additionally, each sample of size n has an equal probability of being the chosen sample. This ...