Investopedia

How Stratified Random Sampling Works, With Examples

Adam Hayes, Ph.D., CFA, is a financial writer with 15+ years Wall Street experience as a derivatives trader. Besides his extensive derivative trading expertise, Adam is an expert in economics and ...
Investopedia

Simple Random Sample vs. Stratified Random Sample: What’s the Difference?

Mary Hall is a editor for Investopedia's Advisor Insights, in addition to being the editor of several books and doctoral papers. Mary received her bachelor's in English from Kent State University with ...
Simon Fraser University

Systematic Random Sampling

The method of systematic random sampling (METHOD=SYS) selects units at a fixed interval throughout the sampling frame or stratum after a random start. PROC SURVEYSELECT chooses the first unit randomly ...
JSTOR Daily

Use of the Generalized Variance and the Gradient Projection Method in Multivariate Stratified Sampling

The authors advocate the use of the generalized variance of the sample means-the determinant of the variance-covariance matrix $D(\overline{y})$ of the means-as a ...
BBC

Sampling data - Intermediate & Higher tier - WJEC

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 ...